UNIVERSITY  OF   CALIFORNIA 


DEPARTMENT  OF  EDUCATION 


GIFT  OF  THE   PUBLISHER 


No.  <>  ,  Received     / 


LIBRARY 

OF  THE 

UNIVERSITY  OF  CALIFORNIA. 


GIFT    OF 


BtOLOSY 
LIBRARY 

G  Class 


INTRODUCTION   TO    ZOOLOGY 


INTRODUCTION  TO  ZOOLOGY 

A  GUIDE  TO  THE  STUDY  OF  ANIMALS 

FOR   THE 

USE   OF  SECONDARY  SCHOOLS 

BY 

CHARLES   BENEDICT   DAVENPORT,    PH.D. 

^ 

ASSISTANT     PROFESSOR    OF     ZOOLOGY     IN     THE     UNIVERSITY     OF    CHICAGO 

DIRECTOR  OF  THE   BIOLOGICAL  LABORATORY  OF  THE   BROOKLYN 

INSTITUTE  OF  ARTS  AND   SCIENCES,   LOCATED  AT  COLD 

SPRING   HARBOR,   LONG  ISLAND 

AND 

GERTRUDE   CROTTY   DAVENPORT,  B.S. 

FORMERLY   INSTRUCTOR  IN  ZOOLOGY  AT    THE   UNIVERSITY   OF  KANSAS 

WITH  THREE  HUNDRED  AND   ELEVEN  ILLUSTRATIONS 


THE   MACMILLAN    COMPANY 

LONDON:  MACMILLAN  &  CO.,  LTD. 
1900 

All  rights  reserved 


COPYRIGHT,  1900, 
BY  THE  MACMILLAN    COMPANY. 


J.  S.  Cashing  &  Co.  —  Berwick  &  Smith 
Norwood  Mass.  U.S.A. 


PREFACE 

THE  general  plan  of  this  text-book  is  at  the  same  time 
both  old  and  new.  Old,  because  it  attempts  to  restore  the 
old-time  instruction  in  Natural  History ;  new,  because 
"  Natural  History  "  is  not  to-day  what  it  was  a  genera- 
tion ago.  The  treatment  will  seem  new  also  in  contrast 
with  modern  text-books  of  zoology,  since  they  are  devoted 
primarily  to  comparative  anatomy,  a  field  upon  which  we 
lay  little  stress. 

This  departure  is  the  outcome  of  a  conviction  that  the 
needs  of  the  secondary  student  are  not  best  met  by  a 
course  in  comparative  anatomy.  That  conviction  is  not 
altered  by  the  circumstance  that  anatomy  is  fundamental 
for  advanced  work  in  zoology  and  physiology,  for  only  a 
sixth  of  the  secondary  students  go  to  college,  arid  proba- 
bly less  than  four  per  cent  of  them  continue  their  zoologi- 
cal work  there.  The  vast  majority  of  secondary  students, 
then,  are  not  to  be  zoologists,  but  rather  men  of  affairs. 
What  the  ordinary  citizen  needs  is  an  acquaintance  with 
the  common  animals  that  may  be  the  companions  of  his 
country  walks,  and  that  may  even  stray  into  Wall  Street, 
Dearborn  Street,  or  Commonwealth  Avenue.  He  wants 
to  know  where  else  over  the  world  the  common  animals 
of  his  State  are  to  be  found  and,  as  a  legislator  or  as  a 
taxpayer,  he  wants  to  know  how  animals  affect  man.  It 
is  more  important  for  him  to  know  these  matters  than  to 
know  the  location  of  the  pedal  ganglion  of  the  snail,  or 

231737 


vi  PREFACE 

to  be  able  to  recite  the  various  ingenious  hypotheses 
of  the  ancestry  of  echinoderms.  Our  conviction  is,  we 
feel  sure,  the  common  conviction  of  college  teachers  of 
zoology,  who  have  often  occasion  to  deplore  the  ignorance 
that  their  students  show  about  common  animals.  It  is 
the  conviction  of  many  other  thoughtful  men  also  who 
have  recognized  that  an  interest  in  nature  is  a  powerful 
agent  in  making  men  morejnoral,  more  capable  of  appre- 
ciating the  world  they  live  in,  and  of  finding  satisfaction 
in  living. 

The  aim  of  the  book  is  indicated  by  its  title.  It  is  not 
a  treatise  on  the  modern  science  of  zoology.  It  is  a  guide 
to  the  study  of  animals,  which  it  is  hoped  may  introduce 
many  students  to  the  sciences  of  comparative  anatomy, 
comparative  embryology,  cytology,  general  physiology, 
variation  and  inheritance,  and  the  others  that  are  grouped 
under  "zoology."  This  book  is  like  a  u  Synoptic  Room  " 
in  the  vestibule  of  a  vast  museum,  containing  the  most 
essential  things  for  those  who  can  go  in  but  a  little  way, 
but  also  fundamental  for  those  who  can  penetrate  farther. 

The  illustrations  of  this  book  have  received  especial  at- 
tention. An  attempt  has  been  made  to  give  a  lifelike  figure 
of  a  representative  of  almost  every  family  mentioned  in  the 
text.  For  courteous  permission  to  reproduce  the  copied 
figures  we  are  deeply  indebted  to  many  publishers  and 
authors.  We  have  to  thank  the  authorities  of  the  Field 
Columbian  Museum  for  original  photographs,  Figs.  301, 
302,  and  305.  Mr.  H.  W.  Menke,  of  the  same  institution, 
kindly  gave  us  permission  to  use  his  interesting  photo- 
graphs of  live  rattlesnakes,  Figs.  261,  262.  To  Mr.  V.  H. 
Lowe,  Entomologist  of  the  New  York  State  Agricultural 
Station  at  Geneva,  N.Y.,  we  are  indebted  for  the  photo- 


PREFACE  Vll 

graphs  marked  V.  H.  L.;  these  are  published  by  permis- 
sion of  the  Director  of  the  Station.  The  majority  of  the 
original  photographs,  designated  by  the  initials  W.H.C.P., 
were  made  by  Mr.  William  H.  C.  Pynchon,  Instructor  in 
Biology  at  Trinity  College,  Hartford.  All  of  these,  ex- 
cepting Figs.  183,  184,  188,  and  203,  are  photographs  of 
animals  occurring  around  the  Biological  Laboratory  at 
Cold  Spring  Harbor,  Long  Island.  They  have  thus  a  cer- 
tain scientific  value  as  indicating  the  fauna  of  that  region. 
As  many  of  these  figures  are  from  living  animals,  probably 
never  before  photographed  in  their  natural  attitudes,  their 
publication  may  be  considered  as  something  of  a  contribu- 
tion to  science.  Of  the  other  photographs,  Figs.  31  a,  122, 
276,  281,  and  288,  marked  D.  and  S.,  were  contributed  by 
Professor  N.  F.  Davis  of  Bucknell  University,  Lewisburg, 
Penn.,  and  Mr.  Ernest  A.  Sterling  of  the  same  institu- 
tion; and  Figs.  127,  251,  and  259  were  contributed  by 
Mr.  E.  R.  Downing,  graduate  student  at  the  University 
of  Chicago.  The  figures  of  birds  by  Louis  Agassiz 
Fuertes  have  been  reproduced  from  "  Citizen  Bird,"  by 
Mrs.  Wright  and  Dr.  Coues,  published  by  the  Macmillan 
Company.  Figures  of  the  types  used  in  the  outline  of 
laboratory  work  have  been  purposely  avoided. 

Finally,  the  authors  have  to  thank  several  secondary 
teachers  who  have  kindly  made  suggestions  and  helpful 
criticisms  on  the  outline  of  laboratory  work  and  the  main 
text.  We  solicit  a  continuance  of  these  favors  to  the  end 
that  this  book  may  become  as  perfectly  adapted  as  pos- 
sible to  the  needs  of  secondary  instruction  in  zoology. 

C.  B.  DAVENPORT. 

GERTRUDE  C.  DAVENPORT. 

CHICAGO,  May  19,  1900. 


CONTENTS 


CHAPTER   I 

PAGE 

THE  GRASSHOPPER  AND  ITS  ALLIES.         .        .      '  .        .         .  .        1 
Key  to  the  four  principal  families  of  Acrididae    ....        2 

APPENDIX  :  Key  to  the  principal  families  of  the  Orthoptera  .       14 

CHAPTER   II 

THE  BUTTERFLY  AND  ITS  ALLIES     .         iv       .       ".-       .         .  .       15 

APPENDICES  :  Key  to  the  principal  families  of  Lepidoptera  .       41 

Key  to  the  principal  families  of  Hymenoptera     .         .  .42 

CHAPTER   III 

THE  BEETLE  AND  ITS  ALLIES   .         ....        .         .  .44 

APPENDIX  :  Key  to  the  principal  families  of  the  Coleoptera  .       58 

CHAPTER   IV 

THE  FLY  AND  ITS  ALLIES         .         .         .         .        ..       ...       62 

APPENDIX  :  Key  to  the  suborders  of  Diptera      .         .  62 

CHAPTER   V 

LlTHOBIUS    AND    ITS    ALLIES           .....            .            .            .  .          74 

APPENDIX  :  Key  to  the  principal  families  of  the  Myriapoda  .       78 

Key  to  the  commoner  species  of  the  genus  Lithobius  .  .       79 

CHAPTER   VI 

THE  SPIDER  AND  ITS  ALLIES    .         .         ..        .    .     ,         .         .  .       80 

APPENDIX  :  Key  to  the  seven  suborders  of  the  Araneina    .  .       95 

ix 


X  CONTENTS 

CHAPTER  VII 

/  PAGE 

THE  CRAYFISH  AND  ITS  ALLIES        .        .        .        .        .        .         .       97 

APPENDICES  :  Key  to  the  six  chief  orders  of  Malacostraea  '        .     122 
Key  to  the  principal  families  of  Podopthalinata  .        .        .     122 

CHAPTER   VIII 

THE  DAPHNIA  AND  ITS  ALLIES          .        .        .        .        .        .  '      .     125 

APPENDICES  :  Key  to  the  five  orders  of  Entomostraca         .      '  .     131 
Key  to  the  principal  families  of  Cladocera  .        .        .        .     131 

CHAPTER  IX 

THE  EARTHWORM  AND  ITS  ALLIES    .         .         .         .         .         .         .     133 

APPENDICES  :  Key  to  the  principal  species  of  Earthworms  of  the 

United  States <.        .143 

Key  to  the  principal  families  of  aquatic  Oligochseta     .        .     144 

CHAPTER  X 

NEREIS  AND  ITS  ALLIES    .        ...        .         .        .         .         .     145 

APPENDIX  :  Key  to  the  more  important  families  of  Polychseta  .     159 

CHAPTER  XI 

THE  SLUG  AND  ITS  ALLIES        .        ,. 160 

Key  to  the  three  orders  of  Gastropoda 160 

Key  to  the  principal  families  of  American  Pulmonata        .        .     161 
APPENDIX  :   Key  to  the  principal  families  of  marine  shelled 
Gastropods  of  the  Atlantic  coast  of  the  United  States     .        .174 

CHAPTER  XII 

THE  FRESH-WATER  CLAM  AND  ITS  ALLIES       .        .        ...        .     178 

APPENDIX:  Key  to  the  principal  families  of  marine  Lamelli- 
branchiata  of  the  east  coast  of  the  United  States    .        .        .     188 

CHAPTER   XIII 

THE  STARFISH  AND  ITS  ALLIES         .        .         .         .        .        .         .     192 

APPENDIX  :  Key  to  the  principal  classes  of  Echinqdermata        .     203 


CONTENTS  XI 
CHAPTER  XIV 

PAGE 

HYDRA  AND  ITS  ALLIES     .         .        .         .        .         .  .      •. .  '     •        .  205 

APPENDICES  :  Key  to  the  principal  subdivisions  of  the  Cnidaria  220 

Key  to  the  families  of  the  Hydroinedusae     .        .        ..       .  220 

CHAPTER  XV 

THE  PARAMECIUM  AND  ITS  ALLIES  .         .         ....        .  222 

APPENDICES  :  Key  to  the  four  classes  of  Protozoa      .        .        .  229 

Key  to  the  subclasses  and  orders  of  Infusoria      .        .        .  229 

CHAPTER  XVI 

THE  SMELT  AND  ITS  ALLIES -  .  230 

APPENDICES:  Key  to  the  principal  orders  of  fishes     .     -  .        .  252 

Key  to  the  six  suborders  of  Teleostei 252 

CHAPTER  XVII 

THE  NEWT  AND  ITS  ALLIES       ........  254 

APPENDICES  :  Key  to  the  orders  of  Amphibia    ....  266 

Key  to  the  families  of  Urodela     .        .        .        .        .        .  266 

CHAPTER   XVIII 

THE  LIZARD  AND  ITS  ALLIES .  268 

APPENDIX  :  Key  to  the  four  orders  of  Reptiles  .     * •.,-••"     .        .  280 

CHAPTER  XIX 

THE  ENGLISH  SPARROW  AND  ITS  ALLIES.        .        .        .     ^r       .  281 

APPENDICES  :  Key  to  the  orders  of  Birds    .     .    .        .      " .        .  314 

Key  to  the  families  of  Passeres  of  northern  United  States  .  315 

CHAPTER  XX 

THE  MOUSE  AND  ITS  ALLIES     ...        ...        .     •    •         •  318 

APPENDIX:  Key  to  the  orders  of  Mammalia   "...        .  331 

CHAPTER  XXI 

THE  DEVELOPMENT  OF  THE  FROG'S  EGG 332 


Xll  CONTENTS 

APPENDIX   I 

PAGE 

OUTLINE  OF  LABORATORY  WORK  IN  ZOOLOGY          .         ,        .         .  337 

INTRODUCTION      .       "..       .         .         .         .  .    -  .  .      .         .         .  337 

EXERCISES  .      ".  .     .         .  ,      .  .      ...        ..*......       .  342 

I.     Grasshopper      .         .        .        .        .    •    .        .    -'  .  342 

IT.     Butterfly   .        .        .        .  -      .        ....  343 

III.  Beetle .  344 

IV.  Housefly  or  Bluebottle  Fly        .        .         ...        .  345 

V.    Lithobius  .        ."       .        .        .        .        .        ,        .  347 

VI.     Spider       .        ...         .        .        /        .         .  348 

VII.     Crayfish    .         .        .         .        .        .   '     ..       .        .  349 

VIII.    Daphnia    .        .        .        .        .        .        .        .      -  .  351 

IX.     Earthworm        .         .        .         .    .     .-       .'     .-.         .  352 

X.     Nereis        ....         .        ...        .  353 

XL     Slug  .         .         .....        .-.-.'..  354 

XII.     Fresh-water  Clam .         ..'356 

XIII.  Starfish      .         .         .         ..'.'.        .         .357 

XIV.  Hydra        .  •     .   :     .        .        .        .        .        .        .  358 

XV.     Paramecium      .        .        ...        .        .        .  359 

XVI.     Smelt         s  '     .        .        .        .         .        .         .  ^     .  361 

XVII.     Newt         ...         ..'....        .         .  362 

XVIII.     Lizard        .        .  '    -  _.  •      .   ...     .    .     J  ,        .         .363 

XIX.     "English"  Sparrow          ,         .        .         .        .         .364 

XX.     Mouse        .        .         .         .         .        .        ...  365 

XXI.     Development  of  the  frog's  egg ..    .   .         .                 .  366 

METHODS  OF  EXAMINATION          .         .         .         ...         .         .  367 

APPENDIX   II 

A  LIST  OF  BOOKS  DEALING  CHIEFLY  WITH   THE  ECOLOGICAL  AND 

SYSTEMATIC  ZOOLOGY  OF  AMERICAN  ANIMALS  ....  369 

APPENDIX   III 

SYNOPSIS  OF  THE  ANIMAL  KINGDOM          .         .         .         .         .         .  383 

GLOSSARY       .'      .        .         .        .        .      V        ....  391 

INDEX      .  397 


INTRODUCTION   TO   ZOOLOGY 


INTRODUCTION   TO    ZOOLOGY 

CHAPTER   I 

THE   GRASSHOPPER   AND   ITS   ALLIES 

Relationships. — The  grasshopper  belongs  to  an  order 
of  insects  called  Orthoptera.1  In  this  group  of  insects2 
there  is  an  incomplete  metamorphosis  during  development, 
so  that  the  general  form  of  the  young  resembles  that  of 
the  adult.  The  anterior  and  posterior  pairs  of  wings  are 
unequal.  The  jaws  are  adapted  for  biting. 

The  name  "  grasshopper  "  is  applied  to  two  families  of 
insects  ;  namely,  the  Acrididse3  and  the  Locustidse.  Both 
of  these  families  have  long  hind  legs,  used  in  jumping,  an 
elongated  body  flattened  from  side  to  side,  and  a  wedge- 
shaped  head  directed  downward  ;  they  differ  in  the  length 
of  the  antennae. 

Habits.  —  The  Acrididae,  or  short-horned  grasshoppers, 
are  found  in  both  hemispheres.  They  live,  for  the  most 
part,  on  the  ground  in  very  diverse  conditions,  such  as  in 
low,  damp  meadows  or  in  dry  uplands,  arid  deserts,  and 
rocky  mountain  sides.  They  are  all  herbivorous,  and  may 

1  6/>067TTepos,  with  straight  (lying  straight  out)  wings. 

2  The  principal  families  of  Orthoptera  may  be  distinguished  by  the 
key  in  the  Appendix  to  this  Chapter,  p.  14. 

3  aKptdtov,  a  small  grasshopper  of  Dioscorides. 


2  ZOOLOGY 

feed  upon  almost  any  green  part  of  plants.  Some  of  thu 
species  are  gregarious  (i.e.  go  in  swarms)  and  may  be 
very  destructive.1 

Melanoplus 2  is  the  prevailing  genus  of  North  America 
and  covers  nearly  all  of  the  continent.  While  in  the 
East  certain  species  of  the  genus  Melanoplus  may  become 
destructive  to  vegetation,  the  injury  done  is  not  so  great 
as  was  formerly  done  by  the  Rocky  Mountain  locust.  At 
various  times  for  some  cause,  probably  drought,  this  locust 
has  migrated  eastward  from  its  mountain  home  in  countless 
millions  and  devastated  our  Western  States  as  far  as  the 
Mississippi  River.  In  1878  to  1877  the  Rocky  Mountain 
locust  was  so  destructive  to  vegetation  in  the  trans- 
Mississippi  region  that  Congress  appointed  a  commission 
to  investigate  the  species.  In  describing  its  effect  the 
commission  reports :  — 

"  Falling  upon  a  cornfield,  the  insects  convert  in  a  few  hours  the 
green  and  promising  acres  into  a  desolate  stretch  of  bare,  spindling 

1  The  following  key  will  aid  in  determining  the  four  principal  Ameri- 
can subfamilies  of  the  Acrididse  :  — 

a\.   Feet  without  a  claw-pad.     Pronotum  covering  all 

the  body.     Fore  wings  lobe-like  .        .        .  Tettigidw 

(Tettix  Shorthorns) 

#2.   Feet  with  a  claw-pad ;  antennae  longer  than  an- 
terior femora. 
61.    Prosternum  without  a  spine. 

d.  The  plane  of  the  vertex  of  the  head  meet- 
ing the  plane  of  the  front  of  head  at  an 
angle,  the  face  looking  down  .  ."  .  Tryxalidce 

(Angle-headed  Shorthorns) 

GZ-    The  planes  of  the  vertex  and  head  round 

over  into  each  other         .        ,        .         .  (Edipodce 

b%.   Prosternum  with  prominent  spine     .         .         .      Melanoplidce 

(Thorn-throated  Shorthorns) 

s,  black  ;  forXa,  armor. 


THE  GRASSHOPPER  AND   ITS  ALLIES  3 

stalks  and  stubs.  .  .  .  Their  flight  may  be  likened  to  an  immense 
snow-storm,  extending  from  the  ground  to  a  height  at  which  our 
visual  organs  perceive  them  only  as  minute,  darting  scintillations, 
leaving  the  imagination  to  picture  them  indefinite  distances  beyond. 
...  In  alighting,  they  circle  in  myriads  about  you,  beating  against 
everything  animate  or  inanimate ;  driving  into  open  doors  and  win- 
dows; heaping  about  your  feet  and  around  your  buildings,  their  jaws 
constantly  at  work,  biting  and  testing  all  things  in  seeking  what  they 
can  devour." 

The  locusts  of  the  Old  World  are  likewise  frequently 
very  destructive.  The  species  that  lives  in  southern 
Europe,  North  Africa,  Asia  Minor,  Syria,  Java,  and  Japan 
is  doubtless  the  locust  of  the  Bible.  The  description 
given  by  the  prophet  Joel  is  very  vivid  and  accurate  :  — 

"  A  day  of  darkness  and  of  gloominess,  a  day  of  clouds  and  of  thick 
darkness,  as  the  morning  spread  upon  the  mountains ;  a  great  people 
and  a  strong ;  there  hath  not  been  ever  the  like,  neither  shall  be  any 
more  after  it,  even  to  the  years  of  many  generations.  A  fire  devoureth 
before  them,  and  behind  them  a  flame  burneth  :  the  land  is  as  the 
garden  of  Eden  before  them,  and  behind  them  a  desolate  wilder- 
ness ;  yea,  and  nothing  shall  escape  them.  The  appearance  of  them 
is  as  the  appearance  of  horses ;  and  as  horsemen,  so  shall  they  run. 
Like  the  noise  of  chariots  on  the  tops  of  mountains  shall  they  leap, 
like  the  noise  of  a  flame  of  fire  that  devoureth  the  stubble,  as  a  strong 
people  set  in  battle  array.  Before  their  face  the  people  shall  be  much 
pained ;  all  faces  shall  gather  blackness.  They  shall  run  like  mighty 
men  ;  they  shall  climb  the  wall  like  men  of  war ;  and  they  shall  march 
every  one  on  his  ways,  and  they  shall  not  break  their  ranks.  .  .  .  They 
shall  run  to  and  fro  in  the  city ;  they  shall  run  upon  the  wall ;  they 
shall  climb  up  upon  the  houses ;  they  shall  enter  in  at  the  windows 
like  a  thief." 

General  Development  of  the  Grasshopper.  —  The  common 
red-legged  grasshopper  lays  its  eggs  during  the  fall  in 
holes  in  the  ground  which  the  female  drills  by  means  of 


4  ZOOLOGY 

the  horny  plates  at  the  tip  of  the  abdomen.  The  eggs, 
thirty  to  one  hundred  in  number,  are  laid  in  a  mass  and 
covered  with  a  gelatinous  secretion.  In  these  holes,  an 
inch  or  so  below  the  surface  of  the  ground,  the  eggs  pass 
the  winter  and  hatch  out  in  early  summer  into  young 
grasshoppers,  looking  like  adults  except  for  their  small 
size  and  the  absence  of  wings.  As  they  grow  larger  they 
moult  several  times,  i.e.  cast  off  their  cuticular  coverings. 
After  each  moult  the  body  is  left  soft  and  colorless,  but 
being  freed  of  its  hard,  tight  casement,  it  is  in  a  condition 
to  grow  rapidly.  After  each  moult  also  the  rudimentary 
wings  (wing-pads)  become  larger,  and  the  relative  sizes  of 
the  parts  of  the  body  change.  Just  before  the  last  moult 
the  pupa  crawls  up  some  vertical  object,  clutches  it  firmly 
with  the  hind  feet,  and  remains  motionless  in  this  position 
for  several  hours.  Then  the  cuticula  splits  along  the 
middle  of  the  back,  the  head  and  body  inside  the  cuticula 
swell,  the  head  emerges  from  the  case,  and  gradually  the 
entire  body  works  forward  out  of  the  old  cuticula ;  not 
easily,  indeed,  but  with  violent  contortions  and  pullings. 
The  legs  and  antennse  are  especially  difficult  to  free  ;  they 
can  pass  out  of  the  joints  of  the  old  skin  only  because 
they  are  soft  and  flabby ;  but  as  soon  as  they  become 
exposed  to  the  air  their  surface  secretion  hardens  into  a 
firm  covering.  The  wings  are  at  first  rolled  up ;  they 
now  expand  broadly,  dry,  and  then  fold  up  in  the  way  we 
see  them  in  the  adult. 

Allies  of  the  Grasshopper.  —  The  Gryllidae,1  or  crickets 
(Fig.  1),  include  cosmopolitan  insects  that  have  short, 
cylindrical  bodies  and  live  chiefly  in  hidden  places,  such 
as  beneath  stones  or  in  holes  which  they  make  in  the 

1  Name  derived  from  sound  made  by  crickets. 


THE  GRASSHOPPER  AND  ITS  ALLIES 


ground.  Their  eggs  are  laid  loosely  in  these  retreats. 
They  feed  on  plants  and,  if  numerous,  may  be  decidedly 
injurious  to  vegetation.  They  make 
a  familiar  chirping  noise,  the  blended 
sounds  of  which,  as  heard  on  a  sum- 
mer evening,  rise  and  fall  in  a  distinct 
rhythm.  The  rate  of  chirp  seems  to  be 
entirely  determined  by  temperature,  so 
that  one  may  compute  the  temperature 
by  means  of  the  formula 

JV_4Q  FIG.      1.— Gryllus, 

J-  =  50  -j ,  cricket.  Nat.  size. 

Photo,  by  W.  H. 

in  which  T  stands  for  temperature,  and        c-  p- 

N  the  number  of  chirps  per  minute.     The  mechanism  by 

which  the  chirp  is  produced  is  as  follows  :   Near  the  mid- 

1    die  of  each  of  the  upper  wings  of 

the  male  cricket  is  a  vein  so  modi- 

lkJl&  fied  as  to  form  a  sort  of  file,  and 

^1  B4  near  tne  margin  of  the   wing  is  a 

^.^^HjN^  thickened  scraper.     When  the  up- 

*^B^P  per  wings  are  brought  in   contact 

^^  jM  above  the  body,  and  the  scraper  of 

^^  fH^^^*"*        one  *s  rubked  across  the  file  of  the 

tjSf  other,  the  wings  are  set  in  vibration, 

ylf  producing  the  call. 

Jf .  An  aberrant  form  of  Gryllidse  is 

the  mole  cricket  (Fig.  2),  whose 
fore  feet  have  become  much  modi- 
fied for  burrowing. 

The  Locustidae,1  or  long-horned 


FIG.  2.  —  Gryllotalpa  bore- 
alis,  mole  cricket.  Nat. 
size.  Photo,  by  W.  H. 
C.  P. 


1  From  the  Latin  name  for  the  locust  and  grasshopper,  as  well  as  the 
lobster. 


6 


ZOOLOGY 


grasshoppers  and  katydids,  are  close  allies  of  the  short- 
horned  grasshoppers  already  denned.     Next  to  the  numer- 


FIG.  3.  —  Orchelimum,  meadow  grasshopper.    Nat.  size.    Photo, 
by  W.  H.  C.  P. 

ous  meadow  grasshoppers  (Fig.  3)  belonging  to  this  group, 
the  katydids  are  the  best  known  of  its  representatives.  The 
katydids  have  their  whole  body  green,  like  the  foliage  they 


FIG.  4.  —  Ceuthophilus,  cricket-grasshopper.    Two-thirds  nat.  size. 
Photo,  hy  W.  H.  C.  P. 

inhabit.     The  wings  are  large;  and  when  the  upper  wings 
are  rubbed  together,  they  vibrate,  and  cause  the  familiar 


THE  GRASSHOPPER  AND  ITS  ALLIES 


note.  Other  members  of  this  group  are  the  cricket-grass- 
hoppers (Fig.  4),  wingless  forms,  of  a  brown  color  and 
arched  profile,  which  live  under  stones  and  rubbish,  and 
also  the  cave  "  crickets,"  which  are 
colorless  and  blind. 

The  Phasmidae^or  walking-sticks 
and  leaf-insects,  display,  to  a  mar- 
vellous degree,  a  protective  resem- 
blance to  the  twigs  and  leaves  among 
which  they  live.  The  most  remark- 
able forms  live  in  the  tropics.  They 
have  large  wings,  which  strikingly 
resemble,  in  form,  color,  and  vena- 
tion, either  living  or  dry  leaves. 
Upon  those  species  which  resemble 
dried  leaves,  blotches  looking  like 
fungous  patches  are  found.  Even 
the  legs  may  be  thin  and  expanded, 
resembling  foliage.  In  our  country 
only  the  twig-like,  wingless  forms, 
or  walking-sticks,  occur.  These  in- 
sects are  furthermore  protected  by 
changes  in  color,  corresponding  with 
the  seasonal  color  changes  in  twig's :  , 

o  »    '    FIG.  5.—  Diapheromera,  walk- 

for  the  young  walking-sticks,  which 

appear  in  the  spring,  are  green  like 

the  twigs,  but  in  the  autumn  they 

become  gray  or  brown.     Figure  5  shows  our  only  common 

northern   species,    Diapheromera  femorata.      It  feeds   on 

leaves,  especially  those  of  the  oak,  and  occasionally  does 

much  damage  to  trees. 


ing-stick  of  northern  U.  S. 
Nat.  size.  Copied  from 
Packard. 


appearance,  spectre. 


ZOOLOGY 


The  Mantidae1  are  popularly  called  praying-mantis,  on 
account  of  the  devotional  attitude  in  which  the  greatly  en- 
larged front  legs  are  held.  Unlike  other  Orthoptera,  they 


FIG.  G. —  Phasmomantis  Carolina.    Praying-mantis  of  southern  U.  S.    Nat. 
size.    Copied  from  Packard. 

are  carnivorous.  They  hunt  and  devour  other  insects  some- 
times larger  than  themselves,  and  even  prey  upon  each  other. 
While  most  of  the  species  are  tropical,  one  species,  PJiasmo- 
manfis  Carolina  (Fig.  0),  is  abundant 
in  our  Southern  States,  and  another 
occurs  in  the  Missouri  valley. 

The  Blattidae,2  or  cockroaches,  are 
especially*  creatures  of  the  tropics ; 
and  those  which  live  in  colder  cli- 
mates frequent  warm  as  well  as  dark 
places.  The  two  which  are  our 
household  pests  have  been  imported 
from  Europe,  —  both  the  small  brown 
"  Croton  bug,"  which  is  found  among 
water-pipes  in  the  kitchen,  and  the 
large  black  species  commonest  in  sugar-refineries,  slaughter- 
houses, and  bakeshops.  They  are  omnivorous,  eating, 


FIG.  7.  —  Wingless  cock- 
roach. Nat.  size.  Photo, 
by  W.  H.  C.  P. 


,  seer,  prophet. 


2  llatta,  roach  of  Pliny. 


THE  GRASSHOPPER   AND  ITS  ALLIES  9 

among  other  things,  breadstuffs,  clothing,  book-bindings, 
bedbugs,  and  other  insects.  We  have  also  a  number  of 
native  cockroaches,  which  live  chiefly  in  fields  and  woods, 
under  stones  and  logs.  Some  of  these  are  wingless  (Fig.  7). 

The  following  groups  are  frequently  excluded  from  the 
Orthoptera,  but  show  a  certain  relationship  with  them  :  — 

The  Forficulidae,1  or  earwigs,  are  rare  in  the  northern 
United  States,  but  commoner  in  the  Gulf  and  Pacific  States. 
In  general  appearance  they  resemble  rove-beetles,  but  differ 
from  them  in  having  a  pair  of  forceps  at  the  posterior  end 
of  the  body.  They  hide,  during  the  day,  in  the  corollas  of 


,  ,^j 


FIG.  8.  — Two  North  American  Odonata,  belonging  to  the  family  Libellululro. 
About  one-half  nat.  size.     Photo,  by  V.  H.  L. 

flowers,  upon  which  they  feed,  and  fly  about  at  night.  The 
name  earwig  seems  to  have  arisen  from  an  unwarranted 
belief  that  these  insects  penetrate  into  the  ears  of  persons 
when  asleep.  They  were  especially  dreaded  on  account 
of  a  fear  that  they  might  thus  penetrate  into  the  brain. 

The  Odonata,2  or  dragon-flies,  have  four  membranous,  net- 
veined  wings,  of  which  the  front  pair  are  never  larger  than 
the  hind  ones.  Their  large  heads  carry  relatively  enormous 
eyes.  Two  groups  of  dragon-flies  may  be  distinguished 
according  as  the  wings,  at  rest,  are  extended  (Fig.  8)  or 

1  forficula,  a  small  forceps. 

2  (55ous,  tooth,  from  the  teeth  of  the  mandibles. 


10 


ZOOLOGY 


folded  together  over  the  back.     Dragon-flies  live  on  the 

wing,  hovering  over  water  and  preying  upon  other  insects, 

especially  mosquitoes.    The  eggs  develop 

in  the  water  into  aquatic  larvse  which  are 

f  quite  unlike  the  adult.  Especially  the 
jaws  are  peculiar,  being  jointed  and  capa- 
ble of  sudden  protrusion,  in  order  to  catch 
the  animals  which  serve  as  prey.  These 
larvae  are  easily  reared  over  winter  in  an 
aquarium,  where  not  only  their  ferocious 
habits,  but  also  their  peculiar  method  of 
breathing  by  means  of  water  taken  in  at 
the  anus,  may  be  observed  (Fig.  9). 

The  Ephemeridee,1  or  May-flies.  The 
adult  May-fly  possesses  finely  veined  fore 
wings,  which  are  much  larger  than  the 
hind  wings.  The  mouth  parts  are  rudi- 
mentary arid  the  abdomen  terminates  in 
two  or  three  filamentous  appendages.  As  their  systematic 
name  implies,  they  have  a  very  ephemeral  existence  in 
the  imago  state.  The  imago  appears  in  swarms  early  in 
the  summer  and  lives  but  a  few  hours,  eating  nothing 
and  depositing  eggs  upon  or  under  stagnant  water.  The 
larvse  feed  upon  small  aquatic  plants  and  insects,  breathe 
by  means  of  gills  placed  on  the  back,  and  live  for  nearly 
a  year,  or  even  for  two  or  three  years,  in  the  immature 
stages.  After  many  moultings  the  apparent  adult  emerges, 
but,  unlike  other  insects,  undergoes  an  additional  moult 
before  laying  its  eggs.  As  the  insect  is  subjected  to  many 
accidents  in  its  long  and  defenceless  life,  each  species  is 
preserved  only  by  an  enormous  fecundity. 

,  a  day,  i.e,  lasting  but  a  day,  short-lived. 


FIG.  9.  —  yEschna, 
old  larva,  or  pupa. 
Nat.  size.  Photo, 
by  W.  H.  C.  P. 


THE  GRASSHOPPER  AND   ITS  ALLIES  11 

White  ants,  or  termites  (Fig.  10),  while  not  true  ants, 
live  a  very  similar  social  or  communal  life.     They  differ 
from  ants  in  the  venation  of  the  net-veined 
wing  (when  present).   White  ants  are  most 
abundant  in  the  tropics,  where  they  build 
great  conical  nests  of  sand   cemented  by 
their  saliva ;   but  they  are   found  also   in 
temperate  countries.     The  common  eastern 
white  ant   (Termes  flavipes}   ranges  from 

_.  '         r     •  °.  .         FIG.  10.  -  Termes 

Massachusetts    southward,    and    lives    in         jiavipes,  white 
wood   or  under  stones.      Three   kinds    or        " ant-"      Nat- 

size.    Photo,  by 

castes  of  white  ants  occur  in  any  com-  w.  H.  c.  P. 
munity :  (1)  workers,  with  small,  round 
heads  and  concealed  mandibles ;  (2)  soldiers,  with  large, 
square  heads,  and  long,  powerful  mandibles ;  and  (3)  the 
royal  class  of  kings  and  queens,  which  have  wings  until 
after  the  marriage  flight.  At  a  certain  time  in  May  the 
males  and  females  from  the  various  colonies  fly  forth 
to  mate,  and  thus  an  interbreeding  takes  place  between 
colonies.  Only  a  few  of  the  pairs,  however,  find  workers 
to  aid  them  in  establishing  a  new  colony.  The  queen, 
after  she  is  established  in  a  new  hive,  merely  produces 
young,  the  abdomen  becoming  immensely  swollen  and 
elongated  to  fifteen  centimetres  with  the  eggs  which  are 
about  to  be  laid.  In  tropical  countries  the  termites  are 
troublesome  to  man  by  injuring  trees  and  devouring  the 
woodwork  of  houses. 

The  order  Neuroptera  includes  certain  insects  which 
differ  from  the  Orthoptera  in  having  larvae  very  unlike 
the  adult,  and  in  having  a  resting  pupal  stage  in  which 
the  metamorphosis  into  the  adult  is  completed.  There  are 
four  membranous,  clear,  net- veined  wings,  and  the  mouth 


ZOOLOGY 


parts  are  used  for  biting.  The  largest  representative  of 
this  group  is  the  Horned  Corydalis  (Fig.  11),  whose  larva 
lives  in  streams  and  is  called  the  dobson.  The  adult 
is  found  among  fallen  leaves  or  on  tree 
trunks. 

The  order  Hemiptera  includes  certain 
insects  which  resemble  the  Orthoptera  in 


\ 


FIG.    12. —  Hygrotrechus,  water-strider.       Nat.    size. 
Photo,  by  W.  H.  C.  P. 

undergoing  an  incomplete  metamorphosis; 
i.e.  in  having  larvae  much  like  the  adults 
in  form,  and  in  having  no  quiet   pupal 
stage.     They  differ 
from  the  Orthoptera 
in  possessing  mouth- 
parts     adapted     to 


FIG.  13.  —  Reduvius,  the 
assassin  bug.  Black. 
Nat.  size.  Photo,  by 
W.H.  C.  P. 


FIG.  11.  —  Cory- 
dalis, the  dobson. 
Two -thirds  nat. 
size.  Photo,  from 
life  by  W.H.C.P. 

sucking. 

The  True  Bugs  (Heteroptera)  in- 
clude a  vast  number  of  generally 
small  insects  with  very  varied  habits. 
Some  of  them  swim  through  the 
water  and  are  known  as  water  boat- 
men ;  others  skip  over  the  surface  of 
the  water  and  are  known  as  water- 
striders  (Fig.  12).  Others,  like  the 


THE  GRASSHOPPER  AND  ITS  ALLIES 


13 


Squash  Bug,  are  destructive  to  plants ;   still  others,  like 
the  Reduviidse,  kill  injurious  insects  (Fig.    13). 


[••^^•^^••••••^••^•^^^^•IggBI^^BB 

F:G.  14. —  Cicada  septemdecem,  the  seventeen  year  locust.     Reduced, 
Photo,  hy  V.  H.  L. 


FIG.  15.  —  Pupal  case  of  cicada.   Two- 
thirds  iiat.  size.  Photo,  by  W.  H.  C.  P. 


FIG.  16.  —  Locanium,  a  scale  insect. 
Remains  of  females  after  production 
of  young  ;  seen  as  swellings  on  the 
bark.  Nat.  size.  Photo,  by  V.H.L, 


14 


ZOOLOGY 


The  Homoptera  include  insects  of  very  diverse  size  and 
form.  The  largest  are  the  cicadas,  or  "locusts"  (Fig.  14), 
some  of  which  have  the  remarkable  habit  of  requiring 
thirteen  or  seventeen  years  for  their  development.  Con- 
sequently these  cicadas 
appear  only  at  intervals 
of  thirteen  or  seventeen 
years.  The  young  bury 
themselves  in  the 
ground  and  live  by 
sucking  juices  from  the 
roots  of  trees.  Eventu- 
ally they  come  to  the 
surface,  leave  their  lar- 
val skin  (Fig.  15),  and 
fly  away  as  full  grown 
cicadas.  In  the  case  of 
our  common  species  of  cicada  there  is  a  brood  every  year. 
Besides  the  cicadas  the  Homoptera  include  the  little 
leaf-hoppers  and  tree-hoppers,  the  very  destructive  scale- 
bugs  (Fig.  16),  and  the  mealy-bugs,  most  of  which  attack 
fruit  trees  and  their  fruits,  and  the  plant-lice,  or  aphids 
(Fig.  17). 


FIG.  17.  —  Schizoneura,  a  woolly  aphis,  on 
apple  twig.    Photo,  by  V.  H.  L. 


APPENDIX  TO  CHAPTER  I 

KEY    TO    THE    PRINCIPAL    FAMILIES    OF    THE    ORTHOPTERA 

a\.    Legs  similar,  fitted  for  running  .        ,        ;        .        ,         Blattidce 

(Cockroaches) 

«2-    First  pair  of  legs  differentiated  for  grasping ;  pro- 
thorax  elongated     .        ;        .        •        .        .        .        Mantidce 

(Praying-man  ti  s) 


APPENDIX    TO    CHAPTER   I  15 

«3.    Legs   similar,  much   elongated,   and  fitted  for  slow 

walking  .........      Phasmidce 

(Walking-sticks) 
a*.    Hinder  legs  stouter  or  longer  than  middle  pair. 

61.    Antennae  shorter  than  body        V        .*      .        .        Acrididce 

(Locusts  and  Short-horned  Grasshoppers) 

&2-    Antennae  longer  than  body. 

GI.    Tarsi  4-jointed        .         .         .         .         .         .      Locustidce 

(Katydids  and  Long-horned  Grasshoppers) 

c2.    Tarsi  3-jointed Gryllidw 

(Crickets) 


CHAPTER   II 

THE  BUTTERFLY  AND   ITS   ALLIES 

Systematic  Position.  —  Butterflies  belong  to  the  insect 
order  Lepidoptera,1  characterized  by  the  possession  of  a 
long,  coiled,  sucking  proboscis;  large,  membranous  wings, 
covered  with  colored  scales;  and  a  complete  metamorphosis. 
They  occur  over  the  whole  globe,  but  become  more  numer- 
ous in  species  in  the  tropics  of  South  America  and  Africa. 
The  number  of  known  species  is  about  twenty-five 
thousand.2 

The  Habits  and  Food  of  Butterflies.  —  The  idea  of  a 
butterfly  should  not  be  limited  to  the  winged  adult  called 
the  imago,  for  strictly  we  may  call  a  caterpillar  a  larval 
butterfly,  and  a  pupa  an  adolescent  butterfly.  But  in  its 
different  stages  the  habits  and  food  of  a  butterfly  change. 
Caterpillars  feed,  for  the  most  part,  upon  plants.  A  few  — 
such  as  the  clothes-moth  and  certain  enemies  of  scale  in- 
sects—  feed  upon  animal  matter.  Any  single  species  of 
caterpillar  feeds  upon  the  foliage  of  a  restricted  number  of 
kinds  of  plants.  At  one  extreme  we  have  forms  which 
starve  unless  they  can  reach  their  own  particular  food 
plant;  at  the  other  extreme  there  are  caterpillars  which 
can  live  upon  the  foliage  of  many  kinds  of  plants,  and 
these  are  consequently  called  polyphagous.  Certain  fami- 

1  Xe7r/s,  scale  ;  irrepbv,  wing. 

2  The  principal  families  of  Lepidoptera  may  be  distinguished  by  the 
key  in  the  Appendix  to  this  Chapter,  p.  41. 

16 


THE  BUTTERFLY  AND  ITS  ALLIES  17 

lies  of  plants  especially  serve  caterpillars  as  food.  Thus  of 
the  hundred  species  of  New  England  butterflies,  eight  feed 
upon  oaks,  eleven  upon  willows,  thirteen  upon  the  Rosacese, 
and  twenty-eight  upon  leguminous  plants.  It  follows  from 
the  restricted  food  of  many  caterpillars,  that  the  range  of 
the  species  must  often  be  determined  by  that  of  its  food- 
plant. 

The  feeding  of  the  butterfly  is  mostly  done  in  the  larval 
stage :  the  pupa  can  take  no  food.  The  imagos  of  many 
species  touch  no  food,  but  in  other  cases  they  take  small 
quantities  of  the  nectar  of  flowers,  the  sap  of  plants,  and 
the  juice  of  fruits. 

The  imagos  fly  in  the  daytime,  especially  in  the  sun- 
shine. Certain  species  are  characteristic  of  the  roadside, 
others  of  meadows,  gardens,  or  woods,  while  still  others  are 
found  flying  everywhere.  Owing  to  its  ordinarily  short 
life,  the  imago  is  usually  found  not  far  from  the  larval 
food-plant,  upon  which  it  lays  its  eggs. 

The  Broods  of  Butterflies  and  their  Polymorphism.  — 
Butterflies  winter  over  in  various  stages,  some  in  the  egg 
stage,  some  as  larvse,  others  as  pupse  or  as  imagos.  Some 
kinds  pass  the  winter  in  either  of  two  stages.  In  whatever 
stage  they  tarry,  the  life  current  runs  very  slow,  and  dur- 
ing this  season  few  changes  take  place.  In  the  spring, 
development  goes  on  rapidly :  the  winter  generation  be- 
comes mature  and  a  summer  generation  is  started.  Fre- 
quently there  is  more  than  one  brood  produced  during  the 
summer,  even  in  the  Northern  States.  Farther  south  two 
and  even  three  summer  broods  are- still  commoner.  Where 
two  or  three  broods  occur  they  may  be  and  usually  are 
quite  dissimilar.  This  is  very  strikingly  illustrated  in  the 
case  of  the  Zebra  Swallow-tail,  Iphiclides  (JPapilio)  ajax, 


18  ZOOLOGY 

of  the  southeastern  United  States,  which  is  multiple- 
brooded.  The  early  spring  form  (marcellus  form)  is  the 
smallest,  and  has  the  tail  tipped  with  white;  the  summer 
form  (ajax)  is  the  largest,  and  has  the  tail  two-thirds 
longer  than  the  marcellus  form.  Other  illustrations  of 
this  seasonal  difference  are  given  by  the  imported  Cabbage 
Butterfly,  the  Gray-veined  White  and  the  Spring  Azure. 
This  dissimilarity  between  the  broods  of  different  seasons 
is  known  as  seasonal  dimorphism  or  polymorphism.  The 
cause  of  the  difference  between  the  different  broods  seems 
to  be  the  dissimilar  climatic,  especially  thermic,  condi- 
tions under  which  they  have  developed.  Mr.  W.  H. 
Edwards  in  this  country,  and  Weismann  and  others  in 
Europe,  have  shown  that,  when  the  summer  form  is  kept 
during  development  in  a  refrigerator,  the  butterfly  has  the 
color  of  the  winter  form. 

Protective  Resemblance  and  Mimicry.  —  Every  one  who 
has  visited  a  natural  history  museum  must  have  noticed 
that  the  polar  mammals  are  apt  to  be  more  or  less  white, 
while  those  which  live  in  tropical  forests  are  dark.  It  is 
easy  to  understand  that  these  colors  in  their  proper  sur- 
roundings make  the  animals  which  wear  them  hard  to 
see.  This  may  be  of  advantage  in  enabling  them  to 
escape  the  observation  of  their  enemies,  which  are  seeking 
for  them,  or  to  avoid  being  seen  by  their  prey  as  they  ap- 
proach. This  general  resemblance  to  their  background  is 
seen  even  in  some  caterpillars,  e.g.  the  tomato-worm,  which 
is  colored  so  exactly  like  the  leaf  on  which  it  feeds  that  it 
is  hard  to  find.  Other  caterpillars,  belonging  to  the  geo- 
metrid  moths,  have  the  color  of  the  twigs  of  the  plant  on 
which  they  feed,  and  the  resemblance  is  heightened  by  the 
way  they  have  of  stiffening  and  standing  out  like  a  branch 


THE  BUTTERFLY  AND  f!T8  ALLIES  19 

from  the  stem.  The  moths  of  the  genus  Catocala,1  which 
fly  by  night,  rest  by  day  on  the  bark  of  trees,  which  they 
so  resemble  as  to  be  almost  indistinguishable.  Still  more 
striking  is  the  resemblance  which  we  find  between  some 
adult  butterflies  and  dry  leaves  as  seen,  for  example,  in  Kal- 
lima,  a  butterfly  of  the  East  Indies.2  The  resemblance  of 
the  butterfly  to  the  leaf  extends  even  to  details,  for  the 
clear  patches  on  the  wing  resemble  holes,  while  little  cir- 


FIG.  18.  —  Catocala  ilia,  the  underwing.     Upper  wings,   bark  color ;  lower 
wings,  black  with  orange  bands.     Photo,  by  C.  Bullard. 

cular  markings  resemble  the  patches  made  by  particular 
kinds  of  fungi.  This  resemblance  of  an  organism  to  in- 
animate objects  in  its  environment  is  known  as  protective 
resemblance. 

There  are  certain  species  of  butterflies  which  appear  to 
be  let  alone  by  birds,  owing  to  their  disagreeable  odor  or 
acrid  taste.  Examples  of  such  are  "the  Heliconidse,  char- 
acteristic of  tropical  South  America,  and  the  Danaidse,  to 
which  family  our  "  Monarch  "  belongs.  Closely  resembling 
1  Fig.  18.  2  Fig>  19. 


20 


ZOOLOGY 


the  Monarch  in  this  country  is  the  "  Viceroy,"  Limenitis 
archippus.  This  resemblance  of  the  edible  Viceroy  to 
the  inedible,  acrid  Monarch,  it  is  believed,  is  sufficient  to 


FIG.  19.  —  A,  Kallima,  the  leaf-butterfly  of  the  East  Indies,  flying;  a,  at  rest. 
B,  Siderone,  another  leaf-butterfly,  flying;  b,  at  rest. 

deceive  even  the  birds,  and  thus  the  Viceroy  gains  con- 
siderable immunity  from  attack.  This  resemblance  of  an 
edible  to  an  immune  species  is  known  as  mimicry.  The 
origin  of  protective  resemblance  and  mimicry  are  both 


THE  BUTTERFLY  AND  ITS  ALLIES  21 

explained  by  the  theory  of  Natural  Selection  or  Darwin- 
ism. Since  either  of  them  is  of  great  utility  to  the 
organism,  their  possession,  even  to  a  slight  degree,  how- 
ever accidentally  gained,  will  give  their  possessor  an  ad- 
vantage over  its  neighbors  in  the  Struggle  for  Existence. 
Consequently  it  will  be  more  apt  to  survive  and  transmit 
its  peculiarity  to  its  offspring.  By  this  means  an  adapted 
race  will  arise  and  crowd  out  the  unadapted. 

Types  of  the  Butterflies.  —  The  group  Papilionidse  in- 
cludes the  butterflies  which  fly  by  day.  An  account  of 
the  most  important  follows.  The  Papilios  (Swallow-tails) 
are  our  largest  butterflies.  Here  belong  the  yellow  Tiger 
Swallow-tail  (turnus),  with  black  stripes,  which  is  found 
over  nearly  the  whole  United  States;  and  the  black  Swallow- 
tail (asterias),  whose  wings  are  crossed  by  rows  of  yellow 
spots,  and  whose  hind  wing  bears  an  orange,  black-eyed 
spot.  Its  larvse  feed  on  wild  or  cultivated  umbelliferous 
plants,  especially  parsnip  leaves. 

The  Cabbage-butterflies  (Pieris)  have  white  or  yellow- 
ish wings,  tipped  and  spotted  with  black,  or  sometimes  with 
orange.  They  hover  over  damp  spots  in  roads  or  fly 
through  garden  patches.  The  larvse  are  very  destructive 
and  feed  on  cabbage  and  other  cruciferous  plants. 

To  the  Nymphs  belong  the  Angle- wings  whose  fore 
wings  are  notched  on  their  outer  edge.  Here  belongs  the 
butterfly  which  we  sometimes  see  on  warm  days  in  winter 
or  early  spring  —  the  Mourning-cloak.  This  has  pur- 
plish brown  wings  with  a  broad  yellow  border,  and  a 
row  of  pale  blue  spots.  The  Graptas  belong  here,  too ; 
they  may  be  told  by  the  silver  spot  on  the  hind  wing. 
In  the  Admirals  the  wings  are  less  deeply  notched. 
The  red  Admiral  is  purplish  black  above,  with  an 


22  ZOOLOGY 

orange  band  and  white  spots  running  obliquely  across 
the  upper  side  of  the  fore  wing.  It  occurs  in  England 
as  well  as  in  the  United  States.  Here  belongs  also  the 
Viceroy,  which  is  not  closely  related,  but  is  quite  similar 
to  the  Monarch  because  the  former  mimics  the  latter. 
They  are  both  of  a  tawny  orange  color,  with  a  white- 
spotted  black  border  on  the  outer  wing  margin.  The 
Monarch  is  the  larger,  and  like  the  birds  has  the  habit 
of  migrating  southward  in  the  fall  and  returning  in  the 
spring.  The  Fritillaries  (Argynnis  :)  include  some  large 
butterflies,  having  numerous  round  and  triangular  silvery 
spots  on  the  under  side  of  the  hind  wing. 

To  the  Lycaenas2  belong  the  Blues,  or  Spring  Azures, 
including  small  satin  or  steel-blue  species  which  exhibit 
marked  seasonable  polymorphism  ;  the  Coppers,  orange- 
red,  or  brown  species;  and  the  Hairstreaks,  or  Theclas,3 
which  are  small,  brown  butterflies,  usually  with  two  tails 
to  the  hind  wing. 

Types  of  the  Moths.  —  These  include  all  Lepidoptera, 
excepting  the  family  of  Papilionidse.  Seven  families  are 
of  rather  large  size  (Macrolepidoptera)  ;  the  remaining  four 
are  of  small  size  (Microlepicloptera). 

The  Sphingidse,4  or  Hawk-moths,  fly  swiftly  and  power- 
fully, and  as  they  hover  over  flowers  at  du;jk  can  hardly  be 
distinguished  from  humming-birds.  The  larvae  have  a 
caudal  horn  or  tubercle.  The  commonest  of  these  are  the 
tomato  or  potato  "  worm,"  green  in  color  and  banded. 
There  are  about  one  hundred  species  of  the  Sphingidse  in 

l'Apyvwls,  the  "silvery,"  a  poetic  name  of  Venus. 
2  MiKouva,  a  poetic  name  of  Venus. 
8  A  Greek  feminine  name. 

4  From  20*7£,  or  sphinx,  a  fabled  monster.  The  larva  of  this  moth 
assumes  an  attitude  like  the  sphinx. 


THE  BUTTERFLY  AND  ITS  ALLIES 


23 


the  United  States.    The  Twin-spotted  Sphinx  (Fig.  20),  so- 
called  from  the  black  spots  of  the  hind  wing,  is  destructive 


FIG.  20.  —  Smerinthus  c/eminatus,  the  Twin-spotted  Sphinx.    Nat.  size. 
Photo,  by  W.  H.  C.  P. 

to  fruit  and  shade  trees.     The  Pandorus  Sphinx  (Fig.  21) 
is  of  a  beautiful  olive  color  ;   its  larva  feeds  on  vines. 


FIG.  21. —  Philampelus  pandorus,  the  Pandorus  Sphinx.     Nat.  size.    Photo, 
by  W.  H.  C.  P. 

The  Xylotropidae l  are  chiefly  medium   to  small,  clear- 
winged  species  which  fly  at  dusk  or  in  daylight.     Their 

,  wood ;  T/o^0w,  to  feed ;  because  the  larvae  feed  on  wood. 


24 


ZOOLOGY 


larvae  live  in  stems  of  squash,  cucumber,  etc.,  and  bore 
into  shrubs  and  trees  (Fig.  22). 

The  Arctiidae,1  or  Tiger-moths,  are  for  the  most  part  con- 
spicuously striped  or  spotted.  The  larvse  are  very  hairy. 
The  best  known  is  the  furry,  brick-red  and  black  Isabella 

caterpillar,  which  can  be  seen 
during  October  in  New  Eng- 
land, hurrying  nervously  in 
search  of  winter  quarters. 

The  Bombycidse2  include, 
as  a  rule,  large  and  thick- 
bodied  moths.  Here  belong 
the  silkworm  moths  —  the 
only  moths  of  use  to  man. 
Of  these,  Bombyx  mori3  is 
the  most  generally  employed 
in  the  manufacture  of  silk.  It 
originally  came  from  China, 
feeds  on  the  leaves  of  the 
white  mulberry,  and  is  reared 
chiefly  in  China,  Japan,  Italy, 


FIG.  22.  —  Larva  of  one  of  the  Sesiidse 
boring  in  stem.  Nat.  size.  Photo, 
by  V.  H.  L. 


and  France.  The  method  of 
culture  is  as  follows  :  The 
eggs  (u  grains  ")  are  laid  in  the  autumn,  kept  over  winter 
in  a  dry,  airy,  and  cool  place,  and  hatched  when  the  mul- 
berry begins  to  send  out  its  leaves.  On  these  leaves 
the  larvse  are  put  to  feed,  and  after  a  month  they  begin 
to  spin.  For  commercial  purposes  the  larvae  are  induced 


1  From  dp/cTos,  bear. 

2  Bombyx-like.     Aristotle  called  the  rustling  silk  /36/x/3os  ;   hence  the 
name  Bonibyx  for  the  silkworm. 

3  morus,  a  mulberry  tree. 


THE  BUTTERFLY  AND  ITS  ALLIES 


25 


to  spin  the  cocoons  on  prepared  twigs  or  straw.     A  few 
days  after  the  cocoon  is  completed  its  inhabitant  is  killed 


FIG.  23. —  Citheronla  regalia,  the  Regal  moth.     Olive  and  red  wings,  yellow 
spots.    Nat.  size.    Photo,  hy  W.  H.  C.  P. 

in  hot  water.     The  cocoon  is  made  of  a  continuous  thread 
about  three  thousand  metres  long,  of  which,  however,  only 


FIG.  24.  —  Larva  of  Citheronia  regalis.      Head  to  left.     One-half  nat.  size. 
Photo,  hy  W.  H.  C.  P. 

about  six  hundred  metres  make   good    silk.     This  long 
thread  has  to  be  unravelled.     The  outer  end  is  loosened 


26 


ZOOLOGY 


by  soaking  the  cocoon  in  hot  water ;  then  several  of  these 
ends  are  brought  together  and  united  to  form  a  single  fibre 

of  raw  silk.     Another  imported  silk-moth 

common  in  parts  of  the  United  States  is  the 
Cynthia1  moth,  whose  larva  infests  Ailan- 
thus  trees.  True  American  forms  are  the 
brown  Polyphemus2  moth,  whose  larva  is 
colored  light  green,  with  oblique  yellow 
stripes;  the  Promethea3 moth,  whose  cocoon 
is  formed  in  a  folded  leaf  which  is  securely 
fastened  by  silk  threads  to  its  twig ;  the 
Cecropia  moth,  expanding  six 
inches,  whose  coarse  tegumen- 
tary  cocoon  is  bound  along 
its  whole  length  to  a  twig;  and  the  nearly 
equally  large  Regal  moth  (Citheronia  regalis, 
Fig.  23),  whose  larva  is  oar  largest  cater- 
pillar (Fig.  24).  All  of  these  species  are 
easily  reared  from  the  larvse  or  cocoons. 

Closely  allied  to  the  Bombycidre  are  the 
Tent-caterpillars,  which  are  never  of  great  size. 


FIG.  25.  —Adult 
female  of  Cli- 
siocampa  dis- 
stria.  From  life. 
Nat.  size.  Pho- 
to, by  V.  H.  L. 


Fin.  20.  —  Adult 
male  of  Clisio- 
cainpa.  From 
life.  Nat.  size. 
Photo,  by  V. 
H.  L. 

These  are 


FIG.  27. —  Egg  masses  of  forest  Tent-caterpillar,  laid  on  branch.    Photo,  by 

V.  H.  L. 

1  A  poetic  name  of  Diana,  from  the  mountain  Cynthus. 

2  The  name  of  the  fabled  one-eyed  giant  blinded  by  Ulysses. 

3  A  name  in  Greek  mythology. 


THE  BUTTERFLY  AND   ITS  ALLIES 


27 


destructive  species,  which  infest  apple  trees  and  even  forest 
trees  (Figs.  25  and  26).  Eggs  are  laid  in  a  ring-like  cluster 
around  a  twig  (Fig.  27).  Here  they  pass  the  winter  and 
hatch  out  in  the  spring  as  young  larvae.  The  larvae  are  gre- 


FIG.  28.  —  Nest  of  CUsiocampa  disstria,  the  forest  Tent-caterpillar,  showing 
the  web  and  the  way  the  larvse  crowd  together  on  it.    Photo,  by  V.  H.  L. 

garious  and  spin  a  tent-like  web,  on  which  they  live  when 
not  feeding  (Fig.  28).     When  ready  to  transform,  they 
spin  a  cocoon  made  of  a  yellow  powder  mixed  with  silk. 
The  Noctuidae1  (Owlet  moths)  are  night  fliers  and  are 
1  From  nox,  night. 


28 


ZOOLOGY 


attracted  by  our  lamplights.      They  are  the  most  numer- 
ous of  all  our  moths,  eighteen  hundred  species  being  known 
from   our   country.     Among   the  largest  members  of  this 
group  are  the  Catocala l  moths  already 
referred  to.     Here   also  are  placed  the 
boll-worm,  which  eats  cotton-pods  and 
green  ears  of  maize ;  the  cotton-worm, 
which   destroys   the   foliage   of  cotton ; 
the    army-worm,    which    devours    grass 
and  young  grain  ;    and  the  myriad  cut- 
worms, of  which  some  gnaw  off  young 
garden  shoots  at  the  level  of  the  ground, 
while  other  kinds  ascend  trees  and  de- 
stroy buds.     To  the  Noctuidss  belong 
also  the  Tussock  moth  (Fig.  29),  whose 
variegated  larva  bears  dense  brush-like 
tufts  of  whitish  hairs  on  the  first  four 
abdominal    segments,   and    is   very    de- 
structive to  shade  trees  in  our  cities  ;  the 
Gypsy  moth,  lately  imported  into  Massa- 
chusetts, where  the  state  has  attempted 
its    annihilation  ;     and    the    Brown-tail 
moth,  also  lately  imported  to  Boston. 
FIG.  29.  — Notoiophus,        The  Gcometridae,  or  measuring-worms, 
Tt  £X  ,!S±   <««,  like  the  Noctuids,  very  numerous 
is   shown   below   a   and    very    destructive.       They    are    so 
^U^"   called  because  the  larva,  have   a  way 
From    life.     Photo.    of  proceeding,  as  it  were,  by  inches  in 
their  locomotion.     One  of  the  most  im- 
portant subdivisions   is  that  of  the   canker-worms,  which 
often  strip  fruit  and  shade  trees  of  their  foliage. 

1  /card,  below  ;  /co\6s,  beautiful. 


THE  BUTTERFLY  AND  ITS  ALLIES 


29 


The  Pyralidae  l  include  among  other  pests  the  bee-moth. 
The  larva  of  this  species  feeds  upon  the  wax  of  the  hive 
and  constructs  silken  galleries  in  the  comb. 

The  Tortricidae 2  contain  numerous  small,  inconspicuous 
moths,  whose  larvae  are,  however,  very  destructive.  The 
codling-moth  is  a  pest  of  the  fruit-grower,  for  the  larva 
bores  into  apples  and  pears,  causing  them  to  fall  prema- 
turely. Many  species  are  called  leaf-rollers,  from  the  fact 
that  the  larva  causes  the  leaf  on  which  it  feeds  to  curl. 


FIG.  30.  — Case-bearing  insects  on  a  twig.     Photj.  from  life  by  V.  H.  L. 

The  Tineidse3  contain  the  smallest  of  the  Lepidoptera. 
Their  wings  frequently  bear  long  fringes.  The  larvae  are 
so  small  that  they  often  live  in  the  interior  of  leaves,  and 
form  winding  or  blotch-like  "mines"  in  them.  The  larvae 
of  some  species  make  a  case  out  of  pieces  of  leaves  united 
by  silk,  and  carry  this  about  with  them.  They  are  known 
as  "  Case-bearers  "  (Fig.  30).  Here  also  belong  the  clothes- 

1  From  Trup,  fire  ;  because  the  ancients  believed  these  insects  to  arise 
from  and  live  in  fire. 

2  tortor,  tortrix,  winder,  from  torqueo,  to  roll  or  wind  ;  with  reference 
to  the  habit  of  twisting  up  leaves. 

3  tinea,  moth. 


30  ZOOLOGY 

moths,  of  which  we  have  three  species.  These  moths  fly 
early  in  May,  and  lay  their  eggs  on  woollen  cloth,  furs,  or 
feathers,  upon  which  the  larvae  feed. 

This  review  of  the  Lepidoptera  shows  us  that,  on  the 
whole,  despite  their  beauty,  they  are  great  enemies  of 
agriculture,  since  most  of  them  feed  on  vegetable  prod- 
ucts. Not  only  do  we  in  this  country  have  an  abundance 
of  native  forms,  but  several  exotic  species  have  been  im- 
ported; and  being  thus  removed  from  their  natural  enemies, 
their  natural  fecundity  has  been  unchecked,  with  the  result 
that  they  have  brought  great  devastation  upon  vast  agri- 
cultural districts.  The  earnest  attempts  of  a  state  to  keep 
down  for  a  while  an  introduced  pest,  even  at  great  expense, 
is  commendable. 

The  Hymenoptera l  include  bees,  wasps,  ants,  and  certain 
less  well-known  insects.  They  all  have  four  similar  mem- 
braneous wings  as  the  Lepidoptera  do ;  but  unlike  the 
Lepidoptera,  their  wings  are  not  covered  with  scales,  but 
are  transparent.  The  mouth  parts  are  formed  for  biting  or 
for  sucking,  but  the  proboscis  is  not  so  long  that  it  rolls  up 
as  in  Lepidoptera. 

The  Hymenoptera  belong  to  one  or  the  other  of  two 
groups, —  the  stinging  Hymenoptera,  in  which  the  female 
is  provided  with  a  sting,  and  the  boring  Hymenoptera, 
which  are  provided  with  an  ovipositor,  or  long  tube,  by 
which  eggs  can  be  placed  at  some  distance  below  the  sur- 
face. To  the  first  division  belong  the  bees,  wasps,  and 
hornets,  certain  digging  or  boring  wasps,  and  the  ants. 
To  the  second  division  belong  certain  species,  —  as,  for 
example,  the  ichneumon  flies,  —  which  are  parasitic  on 

1  vfj.r]i>,  skin,  membrane  ;  trrtpov,  wing. 


THE  BUTTERFLY  AND  ITS  ALLIES  31 

other  insects,  the  gall-flies,  or  gall-wasps,  and  the  plant- 
eating  Hymenoptera.1 

The  bees  (Apidae2)  include  both  social  species  and  others 
which  lead  solitary  lives.  Of  the  latter,  some  dig  their 
nests  in  the  ground ;  others  are  masons,  and  build  their 
nests  of  mud ;  others  are  carpenters,  and  make  tunnels 
through  pithy  plants,  or  even  solid  wood ;  while  still 
others  are  leaf -cutters.  These  leaf-cutting  bees  carve 
circular  disks  from  rose  leaves,  out  of  which  they  make 
cells  for  their  young. 

Of  the  social  bees,  our  native  species  belong  to  the 
genus  Bombus,  —  the  "  bumble  "  bees.  The  bumblebees 
build  nests  in  the  ground. 
The  queens  only  survive  the 
winter.  In  the  spring  each 
queen  chooses  some  mouse 
nest  or  other  ready-formed 
cavity  in  a  meadow,  and 
places  within  it  a  ball  of 

,  .       „       ,      ,          FIG.  31.  —  Bombus,  the  bumblebee. 

pollen.       Upon  this  tood  she       Nat.  size.    Photo,  by  W.H.  c.r. 
lays  eggs,  which  develop  into 

worker  bees.  As  soon  as  the  workers  are  full  grown  they 
begin  the  task  of  gathering  food,  and  the  queen  then  de- 
votes all  her  energy  to  egg-laying.  Later  in  the  season 
males  and  young  queens  also  appear  in  the  nest.  The 
old  and  young  queens  dwell  together  in  harmony  until 
autumn,  when  all  the  members  of  the  colony  perish  except- 
ing the  young  queens,  which  pass  the  winter  in  some 
sheltered  spot  and  form  new  colonies  in  the  spring. 

1  A  key  to  the  principal  families  of  the  Hymenoptera  is  given  in  the 
Appendix  to  this  Chapter,  p.  42. 

2  From  apis,  bee. 


ZOOLOGY 


The  introduced,  semi-domesticated  honey-bees  have 
quite  a  different  social  economy.  In  the  first  place,  the 
nest  is  perennial ;  consequently  the  young  and  old  queens 
cannot  remain  in  the  same  hive,  else  the  nest  would 
become  overcrowded  by  the  presence  of  too  many  families. 
As  }7oung  queens  mature,  the  old  queen  seeks  to  destroy 

them  ;  but  she  is  usually 
forced  out  of  the  hive 
by  the  workers,  a  num- 
ber of  which  accompany 
her.  This  migration  is 
what  we  call  "swarm- 
ing." l  When  several 
young  queens  mature  at 
the  same  time,  duels  or 
repeated  swarmings  en- 
sue until  only  one  queen 
remains.  When  a  new 
colony  is  started  in  a 
hive  or  hollow  tree,  a 
comb  is  formed  of  wax 
secreted  by  the  worker 
bees,  and  into  this  the 
queen  deposits  eggs  des- 
tined to  develop  into 

workers.  Still  later,  eggs  destined  to  form  drones  are  laid  in 
cells  larger  than  those  in  which  workers  develop.  The  de- 
veloping young  workers  and  drones  are  fed  with  honey  and 
bee-bread.  Honey  is  derived  from  the  nectar  of  flowers, 
which  is  lapped  up  by  the  workers,  is  stored  for  a  time  in  the 
crop,  where  it  undergoes  certain  transformations,  and  is  then 

1  Fig.  31a. 


FIG.  'Ma.  — Swarm  of  bees.     Photo,  by 
D. and  S. 


THE  BUTTERFLY  AND  ITS  ALLIES  33 

regurgitated  into  the  cells.  The  nature  of  the  transfor- 
mation of  the  nectar  in  the  crop  of  the  bee  is  not  precisely 
known,  but  it  is  riot  great  enough  to  prevent  the  character- 
istic flavors  of  the  flowers  of  the  buckwheat,  orange,  and 
so  on,  from  being  retained  in  the  honey.  The  bee-bread 
is  made  from  the  pollen  of  the  flowers,  which  is  brought 
into  the  hive  on  the  hind  legs  of  the  workers.  When  a 
new  queen  is  needed  for  the  colony,  and  the  queen  cells 
are  empt%y,  one  may  be  produced  by  the  workers  in  the  fol- 
lowing manner :  The  partitions  between  three  worker  cells 
are  destroyed  and  two  of  the  embryos  are  killed.  The 
enlarged  cell  is  filled  with  a  special  nutritive  compound 
manufactured  by  the  workers  and  known  as  royal  jelly. 
The  remaining  embryo,  fed  upon  this  especially  nutritious 
jelly,  develops,  not  into  a  worker,  but  into  a  queen. 

Of  the  true  wasps  (Vespidie  *),  some  are  solitary;  others, 
like  certain  of  the  bees,  rear  their  families  in  the  nests 
of  other  species  (guest-wasps)  ;    while  still 
others  are  social.     The  last  group  includes 
our   best-known    species.      The    colony    of 
social    wasps  contains  males,  females,  and 
workers.     As   in   the   case   of  bumblebees, 
only  the  females  survive  the  winter,  and  in 
the  spring  they  build  small  nests  and  lay 
worker  eggs.     The  workers,  when  grown,    FIG.  32.— Poiistes. 
enlarge  the  nest  and  care  for  the  numerous      Slightly  reduced. 

.    , ,  ~  .    ,  Photo,  by  W.  H. 

progeny  or  the  queen.      Our  social  wasps      c.  P. 
belong  either  to  the  genus  Poiistes,2  which 
includes   the    ordinary   black,   brown,    or    yellow    bodied 
wasps,  which  build  mushroom-shaped  nests  behind  window 
blinds  and  under  boards  (Fig.  32),  or  to  the  genus  Vespa, 
1  From  vespa,  wasp.  2  TroXio-r^s,  founder  of  a  city. 


34 


ZOOLOGY 


FIG.  33.  — Vespa,  a  hornet. 
Nat.  size.  Photo,  by  W. 
H.  C.  P. 


which  includes  the  black  and  spotted  hornets  and  yellow- 
jackets,  that  build  great  masses  of  paper  combs  enclosed 

in  a  nearly  spherical  gray  paper 
envelope  (Fig.  33).  These  are 
found  attached  to  trees  or  parts 
of  buildings.  The  paper  is  made 
of  finely  masticated  wood-fibre 
cemented  by  a  secretion.  Certain 
yellow- jackets  form  nests  in  the 
ground.  The  hornets  are  well 
known  as  among  the  most  vindic- 
tive of  our  northern  insects,  and 
their  sting  is  capable  of  produc- 
ing considerable  pain.  In  all  Hymenoptera  the  pain  of 
the  sting  is  due  to  the  introduction  of  a  poison  into 
the  body  of  the  victim  through  the  stinging  organ.  This 
poison  is  secreted  by  a  special  gland  of  the  insect. 

The  digger  and  mud  wasps  (Fossoria1)  have  the  most 
varied  habits.  One  of  the  most  familiar  species  is  Pelo- 
pceus,2  which  somewhat  resembles  a  true 
wasp,  but  may  be  easily  distinguished 
from  it  by  the  long,  slender  attachment 
of  the  abdomen  to  the  thorax  and  by  the 
fact  that  the  wings  when  closed  lie  flat 
and  horizontal  (Fig.  34),  while  in  the 
true  wasps  they  are  folded  like  a  fan.  FIG.  34.  —  Digger 
Other  species  bore  into  the  pith  of  plants 
or  make  burrows  in  the  ground.  Many  are 
predaceous,  feeding  on  spiders,  cicadas,  etc. 

The  ants  (Formicidse 3)  constitute  a  well-known  group 
having  features  so  marked  that  other  insects,  excepting 
1  From  fossor,  digger.  2  71-77X65,  slime.          3  From  formica,  ant. 


wasp,  showing  po- 
sition of  wings. 
Nat.  size.  Photo, 
by  W.  H.  C.  P. 


THE  BUTTERFLY  AND  ITS  ALLIES 


35 


the  termites,  will  hardly  be  confused  with  them.  From 
the  termites  ants  may  be  distinguished  by  the  fact  that  the 
first  segment  of  the  abdomen  forms  a  small  knot  or  scale 
lying  between  the  thorax  and  the  remainder  of  the  ab- 
domen (Fig.  35). 

The  intelligence  of  ants  is  notorious.  This  intelligence 
has  developed  in  connection  with  a  highly  organized  social 
life.  This  social  life  is  a  communistic  one.  Homes  are 
built,  food  is  gathered,  \vars  are  made,  and  domains  arc 
defended  bravely  and  loyally  all  for  the  sake  of  the  entire 
community.  The  individual  is  little  regarded,  and  each 


FIG.  35.  —  Camponotus,  the  carpenter  ant.     Uniformly  black.     Shows  scale 
behind  thorax.    Nat.  size.    Photo,  by  W.  H.  C.  P. 

one  is  born  to  a  caste  from  which  escape  is  impossible. 
For,  in  addition  to  the  distinction  of  sex  characteristic  of 
other  species,  we  have  here  workers,  and  these  workers  may 
be  of  different  kinds.  Thus  certain  workers  get  food  and 
care  for  the  young;  others,  which  serve  as  soldiers  and 
defend  the  colony  or  conduct  war,  are  in  some  cases  pro- 
vided with  powerful  jaws.  In  some  species  there  are  three 
or  more  classes  of  workers,  each  having  its  characteristic 
form  of  body. 

Ant  Colonies. — A  colony  is  founded  by  a  female.  On 
warm  days  the  young  males  and  females  may  leave  the 
nests  and  take  flight  in  great  numbers.  This  is  the  mar- 
riage flight  of  the  queens.  Within  a  few  hours  after 


36  ZOOLOGY 

nightfall  of  the  day  of  this  flight  the  males  perish,  while 
the  queens  settle  down  to  the  ground,  tear  off  their  wings, 
and  each  of  them  seeks  an  appropriate  place  to  begin  the 
formation  of  a  new  colony.  If  by  chance  a  queen  is  dis- 
covered by  some  of  her  workers,  she  is  cared  for  by  them; 
otherwise  she  must  get  on  alone.  She  makes  a  small  nest 
and  lays  eggs,  which  quickly  develop  into  workers,  which 
then  assume  the  task  of  constructing  the  nest  of  the  new 
colony.  The  nests  of  our  ordinary  species  consist  simply 
of  tunnel-like  passageways  dug  in  the  ground  and  enlarged 
at  intervals  to  form  small  chambers.  Most  species  dig 
their  nests  preferably  under  protecting  stones  or  the  roots 
of  trees ;  in  other  cases  a  hillock  of  earth  and  twigs,  an 
"ant-hill,"  is  constructed.  These  mounds  may  attain  a 
diameter  of  from  six  to  ten  feet. 

Ant  Language.  —  In  connection  with  their  communal  life 
ants  have  gained  a  power  of  communication.  By  the 
agency  of  their  antennse,  with  which  two  comrades  are 
constantly  stroking  each  other,  they  can  tell  each  other  of 
the  whereabouts  of  food,  of  the  approach  of  an  invading 
army,  or  of  the  need  of  aid.  They  distinguish  members 
of  their  own  community  from  those  of  other  communities, 
and  recognize  one  of  their  number,  even  after  a  long  ab- 
sence, and  receive  it  back  to  the  colony  with  demonstrations 
as  of  joy. 

Social  Life  of.  Ants.  —  To  illustrate  the  complex  social  life  of  ants, 
a  more  detailed  account  is  here  given  of  certain  interesting  species. 
Certain  ants,  such  for  instance  as  our  Formica 1  difficilis^  a  rust-red 
species  often  found  living  beneath  large,  flat  stones,  make  slaves  of 
another  species  of  ant  which  (a  curious  coincidence)  is  a  dark-colored 
species.  In  at  least  one  slave-making  species  the  jaws  have  become 

i  Ant.  2  Difficult. 


THE  BUTTERFLY  AND  ITS  ALLIES  37 

so  modified  to  aid  it  in  capturing  slaves  that  it  is  absolutely  dependent 
upon  its  slaves  for  food,  and  it  would  die  surrounded  by  food  were 
none  of  its  slaves  at  hand  to  feed  it. 

The  Agricultural  Ant.  —  One  of  our  most  interesting  ants  is  the 
Agricultural  Ant  of  Texas  (Myrmica l  molefaciens 2).  This  ant  makes 
a  circular  clearing  about  its  mound,  upon  which  it  allows  only  one 
species  of  grass  to  grow.  Indeed,  some  observers  maintain  that  the 
seed  of  this  grass  is  planted  upon  the  clearing 
by  the  ants.  Certain  it  is  that  the  ripe  seeds 
of  the  grass  are  carefully  harvested  by  the  ants 
and  stored  within  the  chambers  of  their  mound. 
From  time  to  time  the  seeds  are  brought  out  and 
dried  to  prevent  sprouting.  During  rainy  sea- 
sons, when  the  seeds  germinate  despite  all  pre- 
cautions, the  ants  are  said  to  nip  off  the  sprout 
upon  its  first  appearance. 

The  army  ants,  of  which  there  are  several 
species,  occur  in  great  numbers  in  tropical  South 
America.  Like  many  other  species  which  live 
by  hunting,  they  migrate  from  a  locality  after 
having  exhausted  it  of  their  food.  While  on 
the  inarch,  the  young  of  the  species  are  trans- 
ported by  some  of  the  adults.  When  an  army 
of  these  ants  approaches  a  place,  every  living 
animal  endeavors  to  escape.  The  breeding  birds 

must  be  on   the  alert  to  pick  off  the  advance    Fl,a  W.—Pimplapeda- 

hs,  a  parasite  on  the 

guard  to  prevent  them  from  returning  to  the  caterpillar  of  Clisio- 
ar my  with  news  of  the  presence  of  nestlings.  campa.  Upper  figure 
Insects  of  all  sorts,  young  and  old,  fall  a  ready 
prey  to  these  swarms.  Some  spiders  escape  by 
suspending  themselves  by  their  threads,  and  insects  which  resemble 
leaves  often  find  safety  in  keeping  rigidly  still.  When  an  army  of 
these  ants  enters  a  house,  the  inhabitants  find  it  wisest  to  leave 
the  invaders  in  possession,  for  in  a  few  hours  the  house  is  cleared 
of  every  living  thing  —  moths,  cockroaches,  rats,  mice,  all  have  fled 
or  been  devoured. 

The  leaf -cutting  ants  are  another  tropical  American  species.     The 

,  ant.  2  Mole  or  mound  builder. 


38 


ZOOLOGY 


colony  is  very  perfectly  organized.  The  duties  of  the  workers  are 
divided  among  different  gangs.  Thus,  when  a  tree  has  been  selected, 
one  gang  ascends  the  trunk  and  cuts  the  leaves  in  pieces  of  a  definite 
shape.  The  pieces  flutter  to  the  ground,  are  picked  up  by  another 
gang  and  carried  to  the  entrance  of  the  ant-hill,  where  they  are  de- 
posited to  be  carried  into  the  nest  by  a  third  relay.  The  bits  of 
leaves  are  used  to  line  certain  of  the  passageways,  and  a  fungus  is 
grown  upon  them  which  serves  the  ants  as  food.  The  leaves  are 
probably  stored  to  provide  this  fungus  food. 


The  parasitic  Hymenoptera  have  the  habit  either  of  lay- 
ing eggs  in  the  body  of  another  insect,  —  one  of  the  plant- 
lice,  a  caterpillar,  or  other  species,  —  or  else  they  lay  their 
eggs  in  the  nest  of  some  species  of  insect  so  that  the  larva 
can  make  its  own  way  into  the  host  (Figs.  36-38).  The 
long,  tail-like  ovipositors  of  the  female  ichneumon  are,  in 

some  cases,  used  to  drijl 
holes  into  trees  occupied 
by  insect  burrows  so  that 
her  eggs  can  be  laid 
therein.  These  parasitic 
species  are  invaluable  to 
agriculture  in  keeping 
down  injurious  insects. 

The  gall-wasps,  popu- 
larly not  distinguished 
from  the  strict  gall-flies, 
are  familiar  to  us  from 
their  works.  They  lay 
eggs  in  various  kinds  of 
plants,  especially  in  oaks  and  members  of  the  rose  family. 
An  excessive  growth  of  the  plant  tissue,  called  a  gall,  is 
caused  either  by  a  poison  dropped  into  the  plant  with  the 


FIG.  37.  —  Cocoons  of  Microgaster,  a  para- 
sitic hymenopter,  on  a  sphinx  larva. 
Photo,  from  the  living  object  by  V.  H.  L. 


THE  BUTTERFLY  AND   ITS  ALLIES 


39 


egg,  or  by  the  irritation  of  the  developing  embryo.1     The 
galls  of  gall-wasps  are  often  more  or  less  spherical  masses 


FIG.  38.  —  Ophion,  an  Ichneumon  which  infests  caterpillars.    Nat.  size.    Photo, 
by  W.  H.  C.  P. 

which  are  closed,  in  consequence  of  which  the  confined 
insect  must  bore  its  way  out.    The  galls  made  by  the  same 


FIG.  39.  —  Larvae  of  saw-fly  on  grape  leaf.     Photo,  by  V.  H.  L. 
1  Cf.  Fig.  69,  p.  67. 


40 


ZOOLOGY 


species  of  insect  on  one  kind  of  tree  are  quite  similar, 
but  if  the  same  insect  stings  another  species  of  tree,  a 
different  kind  of  gall  is  produced.  Also  when  different 
species  of  gall-wasps  sting  one  and  the  same  leaf,  the  galls 
will  be  unlike.  Hence  the  characteristic  form  of  the  gall 
is  determined  both  by  the  species  of  plant  and  by  the 

species  of  insect  which 
lives  in  it.  It  is  interest- 
ing to  collect  galls,  watch 
for  the  emerging  wasps, 
determine  their  species, 
and  thus  get  their  entire 
life  history.  The  gall- 
wasps  are,  on  the  whole, 
injurious  to  agriculture. 

The  plant-eating  Hy- 
menoptera  are  extremely 
destructive  pests.  The 
young  are  known  as 
"slugs,"  from  their  re- 
semblance to  the  true 
slugs,  which  are  snail-like 
animals.  They  infest  pear 
trees  and  rose  bushes,  leaving  scorched,  dried  leaves  behind 
them.1  Here  also  belong  the  currant-worm  and  the  saw- 
flies  (Figs.  39  and  40),  which  eat  leaves  like  caterpillars, 
but  differ  from  them  in  having  twelve  or  sixteen  prolegs 
instead  of  ten. 


FIG.  40.  —  Eggs  of  Nematus,  a  saw-fly  on 
gooseberry  leaf.     Photo,  by  V.  H.  L. 


1  See  "The  Pear  Slug,"  in  Circular  No.  26,  2d  Series,  U.  S.  Depart- 
ment of  Agriculture,  Division  of  Entomology. 


APPENDIX   TO   CHAPTER   II 


41 


APPENDIX   TO   CHAPTER    II 

KEY    TO    THE    PRINCIPAL    FAMILIES    OF    LEPIDOPTERA 


a\.     Antennae  club-shaped  at  apex  ;  wings  when  at  rest 
held  vertical  (Fig.  19)          .  .. 

«2-     Antennae  usually  having  the  form  of  a  bristle,  spin- 
dle, or  thread,  often  with  a  comb  ;  wings  at  rest 
held  out  flat  (Fig.  23),  or  else  folded  over  body 
like  a  gable  roof  (Fig.  25). 
bi.     Hind  wing  usually  with  one  or  two  dorsal  veins 

[Macrolepidoptera,  large-winged  moths]. 
d.     Antennae  spin  die- shaped  or  keeled,  rarely 
club-shaped  ;  wings  small ;  dusk  fliers. 
d\.     Antennae  prismatic   .        .        .      .  . 

cZ2.     Antennae  not  prismatic,  but 

e\.     attenuated  at  end,  occasionally 
pectinate         .        .        .  -     . 

/i.     Clear  winged  (Sesiina). 
/2.     Wings   speckled,    antennae 
much  longer  than    head 
(Cossina) . 
/3.     Antennae  hardly  longer  than 

head  (Hepialina). 

62-     club-shaped,   occasionally    pec- 
tinate    .        .        .     ,  ; 

C2.     Antennae  bristle-  or  thread-like  ;   wings 

mostly  broad,  night  fliers. 
d\.     Wings  when  at  rest  placed  like  a 
gable  roof  over  body,  or  envelop- 
ing it ;   proboscis  well  developed. 
e\.     Subcosta  of  hind  wing  united  with 
radius  for  a  considerable  dis- 
tance ;  body  hairy  .         .        . 

e2.  Subcosta  of  hind  wing  nearly  or 
quite  distinct  from  radius ;  ab- 
domen ending  conically  . 


Papilionidce 

(Butterflies) 


Sphingidce 
(Hawk-moths) 


Xylotropidce, 

(Wood-borers) 


Zygcenidce 

(Zygenids) 


Arctiidce 

(Tiger-moths) 


Noctuidce 

(Owlet-moths) 


42  ZOOLOGY 

d2.  Wings  as  in  di ;  proboscis  usually 
weak  ;  abdomen  rounded  at  apex ; 
antennae  pectinate  .  .  .  Bombycidce 

(Silk-worms) 
d3.     Wings  rest  horizontally  ;  proboscis 

weak Geometridce 

(Measuring-worms) 
61.     Hind  wing  with  three  dorsal  veins  [Microlepi- 

doptera,  small-winged  moths]. 
Ci.     Wings  not  divided  or  parted. 

di.     Wings  rest  in  gable  fashion,  with 

short  fringe  or  none  at  all. 
e\.     Anterior     wings     elongate-tri- 
angular ;  palps  extending  be- 
yond head       ....  Pyralidce 

(Pyralidsl 

62.  Anterior  wings  much  elongated, 
cambered ;  antennae  with  thick 
basal  segment ;  palps  slightly 
protruding  .  ....•'.  .  Tortricidje 

(Leaf-rollers) 

dz.  Wings  at  rest,  flat  or  enveloping  the 
body ;  the  anterior  wings  with 
long  fringe ;  strongly  developed 
palps -  .  Tineidce 

(Leaf-miners) 

C2.     Wings  divided  or  parted  .        .        .        .    Pterophoridce 

(Plume-moths) 


KEY    TO    THE    PRINCIPAL    FAMILIES    OF    HYMEXOPTERA 

a\.     Trochanter  simple  ;  female  with  sting. 

61.     First  segment  of  the  hind  leg  more  or  less 
compressed,   at   least  on   inner  side,   and 
often  thickly  hirsute    .   •     .       ...        ...    .  .'  Apidce 

(Bees) 

62-  First  segment  of  hind  leg  more  or  less  cylin- 
drical, neither  markedly  broadened  nor 
hairy. 


APPENDIX  TO   CHAPTER  II  43 

Ci.     Anterior  wings  folded  once  lengthwise ; 
antennae  usually   clearly   bent   at   an 

angle Vespidce 

(Wasps) 

C2-     Anterior  wings  not  folded  lengthwise. 
d\.     Abdomen   appended    or   peduncu- 
late, oval  or  broadest  anteriorly, 
gradually  tapering  posteriorly     . 

Superfamily  Fossoria 

(Digger  and  Mud  Wasps) 

d2.  Abdominal  stalk  formed  of  one  or 
two  knots  or  scale-like  rings  ;  an- 
tennse  flagellum-like  .  ;  .  Formicidce 

(Ants) 

«2.     Trochanter  of  two  segments ;    female  with  ovi- 
positor. 

61.  Abdomen  not  sessile,  but  appended  or  pedun- 

culate ;  anterior  rings  without  lancet-cells ; 
hind  wings  with  two  root-cells   . 

Superfamily   Entomophaga 

(Parasitic  and  Gall-producing  Hymenoptera) 

62.  Abdomen  sessile  (or  continuous  with  thorax) ; 

anterior  wing  with  lancet-cell ;  hinder  wing 
with  three  root-cells     .         .      Superfamily       Phytophaga 

(Plant-eating  Hymenoptera) 


CHAPTER   III 

THE   BEETLE   AND   ITS   ALLIES 

BEETLES  (Coleoptera1)  can  be  distinguished  from  other 
insects  by  the  fact  that  the  anterior  pair  of  wings  (elytra) 
are  modified  to  form  two  horny  shields,  covering  the  pos- 
terior part  of  the  body,  while  the  posterior  pair  of  wings 
are  membranous.  The  mouth  parts  are  formed  for  biting.2 

During  development,  the  beetles,  like  the  Lepidoptera 
and  Hymenoptera,  undergo  great  changes  of  form.  These 
changes  may  be  observed  in  the  potato-beetle.  In  this 
species  the  orange-colored  eggs  are  deposited  often  in  a 
very  regular  manner  on  the  under  side  of  the  potato  leaf. 
Here  they  develop  for  several  days.  In  about  a  week, 
however,  the  young,  reddish,  black-spotted  larva,  or  "  grub," 
emerges.  Like  the  adult  beetle,  it  has  three  pairs  of  tho- 
racic legs.  After  feeding  actively  for  two  or  three  weeks, 
the  larva  descends  into  the  ground,  forms  a  naked  yellow 


FIG.  41.  —  Larva  of  Lachnosterna,  the  June  bug,  at  roots  of  aster.     Photo,  of 
living  animals,  nat.  size,  by  V.  H.  L. 


s,  sheath  ;  irrepbv,  wing. 
2  A  key  to  some  of  the  chief  families  of  Coleoptera  is  given  in  the 
Appendix  to  this  Chapter,  page  58. 

44 


THE  BEETLE  AND  ITS  ALLIES 


45 


pupa,  and  emerges  in  about  ten  days  as  an  imago.  From 
two  to  four  broods  are  produced  during  the  year.  The 
adult  beetles  hibernate  in  the  ground,  emerging  and  laying 
eggs  the  following  spring. 

The  larval  habits  of  the  different  kinds  of  beetles  are 
extremely  varied,  quite  as  varied  as  the  habits  of  the  adult. 
The  details  of  these  differences  may  be  best  considered 
when  we  take  up  the  different  kinds  of  beetles. 

The  number  of  species  of  beetles  which  have  been  de- 
scribed is  very  great,  probably  over  one  hundred  thousand. 
Of  these,  over  ten  thousand  inhabit  America,  north  of 
Mexico.  Fortunately  this  vast  number  can  be  included 
within  a  relatively  small  number  of  families.  Leaving 
the  precise  definition  of 
these  families  to  the 
table  in  the  Appendix, 
we  may  here  consider 
certain  of  the  salient 
general  characteristics. 

The  running  beetles 
include  two  principal 
families.  The  first  of 
these  is  the  tiger-beetles 
(Cicindelidse *),  which 

are  colored  bright  brown  or  green.  They  frequent  sunny 
places,  especially  paths  or  sandy  shores,  and  are  extremely 
agile.2  The  larvae  are  hunch-backed  creatures,  have  a  huge 
head  armed  with  long  jaws,  and  live  in  burrows,  at  .the 
entrances  to  which  they  lie  in  wait  for  their  prey. 

The  second  family  of  the  running  beetles  includes  the 
ground-beetles  (Carabidse3  in  narrow  sense).  This  family 


FIG.  42.  —  Three  common  species  of  Cicin- 
dela,  the  tiger-beetle.  Left,  red-copper 
bronze ;  middle,  brown,  with  yellow  mark- 
ings; right,  bright  green,  cream-colored 
markings.  From  Packard. 


1  Derived  from  candela,  candle. 


3  /c<£/>a/3os,  beetle. 


46 


ZOOLOGT 


is  composed  of  about  ten  thousand  species,  of  extremely 
varied  form,  size,  and  coloration.  Most  of  them  are  of  a 
shiny  black  color,  usually  with  longitudinal  ridges  or  rows 
of  punctations  on  the  elytra.1  They  live  on  the  ground, 
and  during  the  daytime  they  are  concealed  underneath 
boards  and  stones,  but  at  night  they  fly  and  climb  trees 
and  shrubs  in  search  of  other  insects.  They  are  most 
abundant  near  watercourses,  and  are  sometimes  found  on 
the  seashore.  Some  species  emit  ill-smelling  fluids,  often 

with  a  popping  sound.  These 
fluids  serve  to  defend  them  from 
their  enemies.  Some  species  are 
vegetable  feeders,  for  instance 
one  species  whose  larva?  are 
destructive  in  the  South  to 
young  Indian  corn. 

The  next  two  families,  Dytis- 
cidae2  and  Gyrinidae,3  include 
beetles  which  are  quite  as  de- 
structive to  animal  life  of  the 
water  as  the  runners  are  to  those 
of  the  land.  The  Dytiscidse  are 
often  large  species,  which  have  long,  thread-like  antennae. 
The  Gyrinidse  have  short  antennae  and  whirl  around  on 
the  surface  of  the  water,  often  in  groups.  Each  eye  is 
divided  into  an  upper  half,  used  for  looking  into  the  air, 
and  a  lower  half,  used  for  looking  into  the  water.  The 
larvae  of  both  of  these  families  have  a  long  and  spindle- 
shaped  or  flattened  body  and  live  in  the  water. 

1  Fig.  43. 

2  BiJTrjs,  diver  ;  5vriK6s,  fitted  for  diving. 

3  From  7u/o6s,  circle  ;  because  this  beetle  swims  in  a  circle. 


FIG.  43.  —  Calosoma  scrutator,  the 
searcher,  a  ground-beetle.  Nat. 
size.  Photo,  by  W.  H.  C.  P. 


THE  BEETLE  AND   ITS  ALLIES 


47 


Another  family  of  aquatic  beetles  includes  Hydrophilus 1 
and  its  allies,  which  are  less  strictly  carnivorous  than  the 
last  two  families.      Their  antennge  are 
short  and  club-shaped,  and  their  bodies 
are  plumper  than  that  of  Dy  tiscus,  which 
is  of  about  the  same  size  and  lives  in 
similar  places. 

The  next  family  includes  certain 
short-winged  beetles  (Staphylinidse 2), 
so  called  because  the  elytra  cover  only 
a  small  part  of  the  abdomen  (Fig.  44). 
These  beetles  ("  rove  -bee  ties")  are  usu- 
ally black  and  of  small  size.  They 
are  very  common  under  decaying  or- 
ganic matter,  stones,  and  other  objects 
lying  on  the  ground.  They  run  swiftly.  Some  species 
mimic  ants  and  wasps.  Not  only  do  they  resemble  these 


FIG.  44.  —  Anthopha- 
gus,  a  staphylinid. 
From  Packard. 


FIG.  45.  —  A  staphylinid  elevating  the  abdomen.    Photo,  by  W.  H.  C.  P. 

Hymenoptera  in  the  general  form  of  the  body,  but  also  in 
the  movements  of  the  tip  of  the  abdomen,  which,  when  the 


>,  water  ;  0/\os,  loving. 
2  <TTa0i>\tj'os,  from  0-Ta0v\iJ,  a  cluster,  is  Aristotle's  name  for  a  certain 
insect. 


48 


ZOOLOGY 


animal  is  irritated,  is  raised  as  though  to  sting  (Fig.  45). 

These  beetles  feed  upon  decaying  animal  and  plant  matter; 

consequently  they  are  useful  scavengers.  Some  species  in- 
habit the  nests  of  ants  and  of  termites, 
but  their  relations  with  their  hosts  are 
unknown.  The  larvae  are  not  unlike  the 
adults,  and  inhabit  similar  situations. 

The  carrion  or  sexton  beetles  (Silphi- 
dse1)  are  usually  of  medium  or  large 
size,  and  are  either  stout-bodied,  with 
red  spots  on  each  elytron  (Necro- 
phorus2),  or  very  much  flattened  and 

FIG.  46.  —  Silpha  amer-        .,,,,.         T        -,     ,     .        /o.,    ,        T^.       4f*^ 

icana,  a  carrion  bee-    With  thin-edged  elytra  (Silpha,  1  ig.  46). 

tie.  From  "  standard    The  species  of  Necrophorus  are  power- 
Natural  History." 

lul  animals.      When  one  or  more  pairs 

of  these  beetles  discover  a  dead  bird  or  small  mammal 

on  the  ground,  they  dig  out  the  earth  from  underneath 

and    pile    it   upon    the    animal   until    eventually  the  car- 

cass is   entirely  buried.      Then 

the    female    deposits    her    eggs 

upon  the   body,  so  that  a   rich 

supply  of  food  is  provided  for 

the   young   larvae   which    hatch 

from  the   eggs.      The  members 

of  the  genus  Silpha  do  not  bury 

a  carcass,  but  live  and  rear  their 

young  beneath  it. 

While  the  families  of  beetles  hitherto  considered  are 
in  general  useful  to  man  by  acting  as  scavengers  or  by 
destroying  insects  injurious  to  vegetation,  we  have  now 


FIG.  47. — Anthrenus,  the  muse- 
um pest,  a  dermestid.  Left, 
larva ;  middle,  pupa ;  right, 
adult.  From  Packard. 


7,  an  ill-smelling  insect. 
2  veicpfa,  a  dead  body  ;  0<?/>w,  to  bear. 


THE  BEETLE  AND  ITS  ALLIES 


49 


to  consider  a  family,  that  of  the  Dermestidae,1  which  is 
economically  directly  injurious  in  a  variety  of  ways.  The 
species  of  this  family  include  small,  oval,  or  elongated 
beetles  with  gray  or  brown  markings,  which  are  due  to 
scales  and  can  be  rubbed  off.  The  larvae  are  fuzzy,  and 
are  more  injurious  than  the  imagos.  They  feed  on  wool, 
leather,  fur  of  all  sorts,  as  well  as  on  dried  and  salted 
meats.  Our  most  destructive  species  have  been  imported 
from  Europe.  One  of  them  is  the  carpet-beetle  or  "buf- 
falo-bug," which  lives  upon  carpets  and  clothing.  The 
museum  pest  is  a  closely  related  species  which  works  sad 
havoc  with  insect  collections,  unless  these  are  subjected 
several  times  a  year  to  the  poisonous  fumes  of  carbon 
disulphide  (Fig.  47). 

The  stag  beetles  (Lucanidae2)  have  received  their  com- 
mon name  from  the  resemblance  of  their  long,  often 
branched  mandibles  to  the  antlers  of  a 
stag.  The  plates  of  the  club-shaped 
antenna  cannot  be  brought  compactly 
together,  as  in  the  next  family.  The  adult 
beetles  live  on  the  sap  of  trees,  and  the 
larvae  bore  into  the  wood  of  the  roots  and 
trunk.  The  common  large  stag-beetle, 
which  is  often  attracted  into  our  houses  by 
lamplight,  is  Lucanus  dama.  In  the  South 
the  giant  stag-beetle  (Lucanus  elephans)  is 
found,  with  mandibles  which,  in  the  case  of 
the  male,  are  more  than  three-fourths  the  length  of  the  body. 

Closely  allied  to  the  last  is  the  great  family  of  lamelli- 
corn3  beetles,  in  which  the  ends  of  the  antennae  bear  flat, 

1  Sepfj.rjvT'/is  (5^/tyia,  skin;  &r0iw,  to  gnaw),  a  worm  which  destroys  pelts. 

2  From  lucus,  grove.  3  lamella,  a  small  plate  or  leaf ;  cornw,  horn. 

B 


FIG.  48.—  Dorcus, 
a  stag  -  beetle. 
Nat.  size.  Photo, 
by  W.  H.  C.  P. 


50 


ZOOLOGY 


i 


closely  applied  plates.     This  family  includes  many  very 

large  insects.     We  can  separate  it  into  two  groups,  —  the 

scavengers  and  the  leaf-chafers. 

The  scavenger  larnellicorns,  commonly  known  as  tumble- 
bugs,  live  in  the  dung  of  horses  and  cows,  which  they  form 

into  balls  and  roll  long  distances 
(Fig.  49).  The  dung-rolling  habit 
has  long  excited  interest;  indeed, 
among  the  Egyptians  it  was  a 
source  of  superstition.  So  high 

^f  ^  'JiH mm.  was  the  veneration  of  this  people 
for  this  their  sacred  beetle,  that 
they  reproduced  it  in  their  paint- 
ings and  sculpture.  The  ball  of 
dung  is  really  intended  for  the  dep- 
osition of  an  egg,  and  it  is  rolled 
by  both  males  and  females  to  a  hole 

in  the  ground  which  has  been  dug  in  a  safe  place  for  its 

reception. 

The  leaf-eating  lamellicorns  include  the  May-beetles  or 

"June-bugs"     (Laclmosterna1)    which    are    attracted    by 

lamplight   at  night.      They  enter  with   a 

busy  humming  sound,  soon  come  in  violent 

contact  with  the  wall  or  a  piece  of  furni- 
ture, and  fall  heavily  to  the  floor.    They 

feed  at  night  upon  the  foliage  of  trees  and 

shrubs.     Another  common   species  is  the 

rose-bug,2  which  bears    the    name  Macro- 

dactylus  3  bubspinosus.     It  is  destructive  to 

the  blossoms  and  young  fruit   of  grapes, 


FIG.   49.  —  Copris,  a  tumble- 
bug^  Nat.  size.   Photo,  by 


,  sheep's  wool ;  vrtpvov,  the  chest. 
2  Fig.  50.          3  /ia/c/)6s,  large  ;  5ci/rriAos,  finger. 


FIG.  50.  — Macro- 
dactylus,  the 
rqse-bug.  Nat. 
size.  Photo,  by 
W.  H.  C.  P. 


THE  BEETLE  AND   ITS   ALLIES 


51 


roses,  and  other  members  of  the  plant  family  Rosaceae. 
The  larvae  of  the  May-beetles  are  the  fat,  whitish,  bowed 
grubs  which  are  often  found  in  the  spring  in  the  soil  where 
they  have  passed  the  winter.     They  are 
very  destructive,  for  they  feed  on  roots  of 
grass,  herbs,  and  shrubs  (Fig.  41). 

Another  family  of  beetles  very  destruc- 
tive to  trees  is  that  of  the  metallic  wood- 
borers  or  Buprestidae.1  The  adults  are 
found  upon  flowers  and  the  bark  of  trees, 
where  their  metallic  colors  glitter  in  the 
sunshine  (Fig.  51).  The  larvae,  which 
have  relatively  enormous  heads,  bore  FlG' 

J  ruftpes,   a  metallic 

beneath    the   bark  of   trees   or   into    the 

wood.     This  family  reaches    its   highest 

development  in  the  tropics. 

Closely  allied  to  the  foregoing   is  the  family  of  click 

beetles  or  Elateridae.2  These  have  the  power,  when  placed 
on  their  backs,  of  leaping  into  the  air  by 
means  of  a  special  device  on  the  under 
side  of  the  animal  (Fig.  52).  The  larvae, 
called  "  wire- worms "  because  of  their 
round,  hard  bodies,  live  under  the  bark 
.of  trees  and  in  rotten  wood  or  upon  vegeta- 
tion in  the  ground.  They  are  most  de- 
structive to  germinating  grain,  especially 

FIG.  52.— One  of  the  maize.  It  requires  several  years  for  them 
to  mature. 

The    fireflies    (Lampyridae3)    make    up 


wood-borer.  From 
"Standard  Natural 
History." 


click  beetles. 
Nat.  size.  Photo, 
by  W.  H.  C.  P. 


s,  among  the  ancients  a  poisonous  beetle,  living  in  grass  by 
swallowing  which  oxen  (/Sous)  swell  out  (TT/^W)  . 

,  driver.  8  Xd/*7ra>,  to  shine  ;  otpd,  tail. 


52 


ZOOLOGY 


another  and  a  well-known  family.     They  are  distinguished 
by  soft  wing-like  elytra  and  by  the  great  expanse  of  the 

thoracic  shield,  which 
partly  or  wholly  covers 
the  head.  Certain  non- 
luminous  species  live  on 
flowers,  especially  the 
golden-rod  ;  the  lumi- 

i 


FIG.  53.  —  Photuris,  a  firefly.  a,  larva ; 
b,  adult.  The  lines  to  the  left  of  figures 
represent  actual  lengths  of  animals.  From 
Packard. 


nous  species  are  noctur- 
nal. The  light-giving  or- 
gan lies  in  the  abdomen. 
The  larvae  also  are  lumi- 
nous and  are  known  as 
glow-worms  (Fig.  53). 

A  family  of  consider- 
able economic  import- 
ance is  that  of  the  Tene- 
brionidae,  so  called  from 

the  principal  genus   Tenebrio,1  the 

larva  of  which,  known  as  the  meal- 
worm, occurs  in  flour   and    cereals 

and  looks  much  like  a  wire-worm.2 

The  adult  beetle  is  black  and  about 

one-half   an    inch    long    (Fig.    54). 

The  family  is  not  abundant  in  the 

northeastern    part    of    the    United 

States. 

Several    kinds    of    adult   beetles 
be   found   under   the    bark    of 


can 


FTG.  54. — Tenebrio, the  meal- 
worm. Left,  larva ;  right, 
adult.  From  Leunis. 


1  Miller,  because  it  lives  in  flour. 

2  These  larvse  are  reared  by  bird-fanciers  for  bird  food,  and  may  be 
obtained  in  bird  stores. 


THE  BEETLE  AND   ITS  ALLIES 


53 


trees,  but  these  are  mostly  carnivorous  and  are  seeking 
their  prey  there.  The  minute  bark-borers  or  engraver 
beetles  (Scolytidse1),  however,  feed  on  the  innermost  layer 
of  bark.  As  they  eat  in  lines,  a  pattern  is  formed  which 
is  characteristic  for  each  species.  Along  these  lines,  niches 
are  made  in  which  eggs  are  laid  and  larvae  hatch.  The 
borings  are  injurious  to  the  trees,  often  causing  their 
death.  Herbaceous  plants  also  are  infested  by  certain  spe- 
cies. An  example  is  the  destructive  Pine  Borer  (Fig.  55), 
which  is  common  throughout  the  United 

States  and  Canada. 

One  of  the  most  injurious 

of  all  the  families  of  beetles 

is  that  of  the  weevils  (Cur- 

culionidse2).  These  beetles 

are  small,  and  their  heads 

are  drawn  out  into  a  long 

snout  by  which  they  bore 

holes   in    plant    tissue    to 

receive    their    eggs    (Fig. 

56).      The  dull  colors   of 

the  beetles  render  them  in- 
conspicuous to  insect-feeding  birds.  The  number  of  species 
is  reckoned  at  over  ten  thousand,  and  the  family  is  of  world- 
wide distribution,  its  dispersion  having  been  aided  by  com- 
merce. Grain-weevils  are  great  pests  in  stored  wheat,  rice, 
or  maize.  They  also  oviposit  in  the  planted  seeds.  Buds 
are  attacked,  and  nuts,  stone  fruit,  and  fleshy  fruits  are 
made  "  wormy  "  by  them. 

Extremely  destructive  also  is  the  great  family  of  long- 


FIG.  55.  —  Den- 
droctonus,  an 
engraver  bee- 
tle. Magnified 
2.5  times.  From 
"Standard  Nat- 
ural History." 


FIG.  56.  —  Balani- 
nus,  a  weevil,  of 
brown  color. 
From  Packard. 


1  From  (r/coXi57rTw,  to  mutilate. 

2  curculio,  a  grain-weevil. 


54 


ZOOLOGY 


horned    beetles,    "buck-beetles,"    (or    Cerambycidse1),   of 
which    about   six    hundred   species    are   known  in   North 

America  alone.  The  an- 
tennae and  legs  of  these 
beetles  are  very  long.2  The 
larvae  bore  into  even  the 
hardest  woods,  and  live  in 
the  wood  for  two  or  three 
years.  Timber  and  shade 
trees  are  thus  greatly  dam- 
aged. A  favorite  collect- 
ing ground  for  Ceramby- 
cidae  is  the  golden -rod, 
where  the  black,  yellow- 
banded  locust  borer,  Cyllene 
robince  (Fig.  59),  is  pretty 
sure  to  be  found. 
Still  another  destructive  family  is  that  of  the  leaf-eating 
beetles,  —  the  Chrysomelidae,3  to  which  the  potato-beetle 
belongs.  These  beetles  are  thick 
and  round  in  shape.  They  lay 
their  eggs  upon  the  leaves  of 
plants.  The  larvae  feed  on  the 
leaves  or  burrow  in  the  stem. 
Usually  the  larva  is  conspicu- 
ously colored  and  exposed,  and 
relies  for  protection  upon  its  dis- 
agreeable odor  and  taste.  The 
most  destructive  species  to  agri- 
culture in  the  northern  United 


FIG.  57.  —  Prionus  latlcollis,  a  long- 
horn.  Black.  Nat.  size.  Photo,  by 
W.H.C.P. 


FIG.  58.  —  Orthosoma  bnui- 
neum,  the  straight -bodied 
Prionid.  Brown  color.  Nat. 
size.  Photo,  by  W.  H.  C.  P. 


;,  a  beetle  with  long  horns.  2  Figs.  57  and  58. 

3  chrysomela,  gold  beetle,  from  xPVfffa>  gold,  and  /x^Xoi/,  apple. 


THE  BEETLE  AND   ITS   ALLIES  55 

States  is  the  ten-lined  Colorado  potato-beetle,  Doryphora1 
decemlineata.  Until  about  1859  this  species  fed  upon  the 
sand-bur  {Solanum  .ro stratum),  at  the  eastern  base  of  the 
Rocky  Mountains  and  south  into  Mexico. 
With  the  advent  of  settlers  and  the  plant- 
ing of  the  cultivated  potato  {Solanum 
tuberosum,  a  native  of  Mexico),  this  more 
thrifty,  cultivated  species  was  adopted  as 
its  food-plant,  and  the  potato-beetle  began 
its  eastern  migration.  It  spread  slowly  at 
first,  but  within  fifteen  years  had  reached 
the  Atlantic  coast.  The  little  red,  yellow, 
and  black  asparagus-beetle^  the  yellow, 
black-striped  cucumber  and  melon  beetle, 
the  tortoise-beetle,  whose  broad,  iridescent, 
translucent  elytra  are  conspicuous  on  the 
leaves  of  the  morning-glory,  nettle,  and 
other  plants,  all  belong  to  this  family. 

So  long  has  become  our  list  of  destructive 
beetles  that  it  is  with  satisfaction  that  we 
turn  at  the  end  to  a  family  which  is  almost 
wholly  beneficial  to  the  vegetable  kingdom, 
as  well  as  to  most  vegetable-feeders,  includ- 
ing man.  This  is  the  ladybird  family,  FIG.  59.  —  Cyliene 
Coccinellidae.  These  beetles  are  preda-  ™Un^ ,the  ^cust 

x  borer,   found    on 

ceous,  both  in  the  larval  and  adult  stages,  the  golden  -  rod. 
feeding  upon  small  insects  and  insect  eggs  ^hpt0'  by  w>  H'' 
(Figs.  60  and  61).  They  are  especially 
active  in  freeing  plants  from  scale-insects  and  plant-lice. 
So  rapidly  do  the  latter  multiply  that  were  it  not  for  the 
voracious  larvse  of  the  ladybird  most  plants  would  be 
1  5o/>u06/>os,  spear-bearing. 


56 


ZOOLOGY 


FIG. 
Anatisocel- 
lata.  Adult. 
Nat.  size. 
Photo,  by 
V.H.L. 


destroyed  in  a  single  season.     The  larvae  of  the  ladybirds 
are  dark,  spotted,  and  hirsute.     One  of  the  commonest  of 

four  eastern  ladybirds  is  a  red- 
backed,  two-spotted  one  (Adalia 
bipunctata). 
The  food  of  beetles  is,  as  we 
have  seen,  extremely  varied, 
more  varied,  indeed,  than  that  of 

FIG.  CO. —Pupa  of  , ,  ->         £  .  -, 

Anatisocellataon    anJ  other  or<kr  of  insects ;  WOod- 

a  leaf.   Nat.  size,  fibre,  bark  of  living;  or  dead  trees, 

Photo,  by  V.H.L.    .       „         ,  ,.  .      .. 

leaf  and  stem  tissue,  nuts,  fruits, 
grains,  insects,  adult  and  larval  and  dead  animals  of  vari- 
ous sorts,  are  all  utilized  by  them  as  food.     Those  beetles 
which    destroy   living    plants,    or    which    feed    on    fruits 
and  grains  utilized  by   man,  those  which  burrow  in  tim- 
ber, devour  meat  or  articles  of  human 
industry  and  collections  prized  by  man, 
may  be  ranked  as  economically  injuri- 
ous.    One  species,  indeed,  is  injurious 
as  a  parasite  of  a  useful  animal ;  this  is 
a  curious  beaver  parasite,  Platypsylla1 
castor  ia?    In  so  far  as  certain  predaceous 
beetles    feed    upon    other    carnivorous 
species   of   insects,   as   do   certain   tiger 
FIG.  02.  -  Platypsylla    ancl  carrion  beetles,  or  upon  small  fish, 
castoria,  the  beaver    as  do  some   of  the  Dytiscidse,  or  upon 
Packard.  *    domestic  bees,  like  certain  allies  of  the 

weevils,  they  may  be  indirectly  injur- 
ing man.  Of  all  the  families  of  beetles,  probably  the  leaf- 
eaters  cause  greatest  destruction ;  next  to  them  come  the 
weevils,  followed  by  the  Cerambycidie  and  the  others. 

1  irXarvs,  broad  j  i/^XXa,  a  flea.  2  Fig.  62. 


THE  BEETLE  AND   ITS  ALLIES  57 

Every  part  of  the  plant  has  its  coleopterous  enemy.  As 
Le  Conte  and  Horn  have  said:  "As  the  function  of  the 
Cerambycidce  is  to  hold  the  vegetable  world  in  check  by 
destroying  woody  fibre,  the  Bruchidse  (weevils)  effect  a 
similar  result  by  attacking  the  seeds,  and  the  Chrysome- 
lidse  by  destroying  the  leaves." 

The  list  of  beetles  directly  or  indirectly  useful  to  man 
is  small.  The  carrion-beetles,  tumble-bugs,  and  rove- 
beetles,  which  feed  upon  decaying  animal  and  vegetable 
matter,  are  useful  as  scavengers.  Of  those  which  serve  us 
by  killing  other  insects  injurious  to  vegetation,  the  lady- 
bird beetle  stands  first.  The  economic  importance  to  us  of 
this  one  family  can  hardly  be  estimated.  Different  kinds 
of  ladybirds  feed  on  different  species  of  insects.  At  one 
time  it  seemed  that  the  orange  industry,  if  not  that  of  fruits 
in  general,  was  doomed  in  California  on  account  of  the 
destruction  wrought  by  the  introduction  of  a  scale-insect. 
As  the  insect  had  been  imported,  we  had  no  native  beetle 
which  attacked  it.  Search  was  made  abroad,  and  a  lady- 
bird beetle  was  found  in  Australia  which  feeds  on  this 
particular  scale-insect.  The  Australian  beetle  was  intro- 
duced into  California,  and  now  the  scale-insect  is  subdued. 
The  larvae  of  some  of  the  checkered  beetles  J  feed  upon  the 
larvse  of  boring  beetles,  while  the  larvse  of  tiger-beetles 
watch  at  the  mouth  of  their  burrows  for  other  insects  upon 
which  they  feed.  Carabid  beetles  are  said  to  ascend  trees 
in  search  of  canker-worms.  Larvae  of  ground-beetles  prey 
upon  the  pupating  plum  Curculios.  Other  beetles  eat  cut- 
worms, and  infest  the  common  wasps. 

One  beetle,  the  blister-beetle,  known  in  the  markets  as 

1  A  family  of  rather  small  beetles,  living  in  flowers  and  on  trees,  and 
often  with  contrasting  colors. 


58  ZOOLOGY 

the  Spanish  fly,  has  been  for  ages  used  as  a  drug.  When 
disturbed,  there  exudes  from  the  joints  of  this  insect  a 
liquid  serving  as  a  protection,  since  it  burns  or  blisters  the 
disturber.  This  property  is  retained  in  the  extracted  or 
dried  substance.  The  article  sold  in  drug  stores  is  ob- 
tained from  crushing  the  dried  beetle.  The  larvae  of  vari- 
ous beetles  have  been  prized  as  food  by  certain  peoples 
from  the  Romans  of  Pliny's  time  down  to  the  present, 
for  they  are  eaten  with  relish  by  certain  tribes  of  South 
American  Indians.  Fireflies  sewn  in  lace  are  sometimes 
worn  by  the  Spanish  and  Cuban  women  as  adornments  for 
evening  dresses,  while  other  beetles  with  particularly  hard 
and  beautifully  colored  and  iridescent  wing-covers  are  used 
as  settings  in  hat  ornaments  and  buckles,  as  well  as  in 
jewels. 

APPENDIX   TO   CHAPTER  III 

KEY    TO    THE    PRINCIPAL    FAMILIES    OF    THE    COLEOPTERA 

(The  terminology  of  the  key  may  be  understood  by  reference  to  the  figures 

on  page  59.) 

a\.    Hind  tarsi  with  five   segments,    as  likewise  also 
usually  the  other  tarsi,  certain  aquatic  families 
excepted  [Pentamera]. 

fti.     Elytra,  short,  exposing  nearly  whole  of  abdo- 
men     ...         .         .         .         .         .     Staphylinidce 

(Rove-beetles) 
&2-     Elytra,  nearly  or  quite  covering  abdomen. 

c\.  Antennae  bent,  first  segment  long,  ter- 
minating in  a  club  made  of  applied 
lamellae. 

di.     Lamellae   closely   applied   and    flat- 
tened    ......  LamelUcornia 

(Lamellicorns) 

dz.    Lamellae  not  closely  applied ;  man- 
dibles very  large    ....          Lucanidce 

(Stag-beetles) 


APPENDIX  TO   CHAPTER  III 


59 


FIG.  G2a.  —  Under  surface  of  Harpalus, 
a  ground-beetle.  After  Le  Conte. 
«,  ligula  ;  b,  paraglossse;  c,  supports 
of  labial  palp1 ;  d,  labial  palp ;  e,  men- 
turn  ;  /,  inner  lobe  of  maxilla ;  g, 
outer  lobe  of  maxilla ;  h,  maxillary 
palp ;  i,  mandible ;  k,  buccal  open- 
ing ;  I,  gula  or  throat ;  mm,  buccal 
sutures ;  o,  prosternum ;  pf,  epister- 
num  of  prothorax ;  p,  epimeron  of 
prothorax;  q,  qf,  q",  coxae;  r,  rf,  r", 
trochanters ;  s,  .',',  sff,  femora  or 
thighs;  t,  t',  t",  tibiae  ;  v,  v2,  v3,  etc., 
ventral  abdominal  segments;  w, 
episterna  of  mesothorax  (the  epim- 
eron just  behind  it)  ;  x,  meso- 
sternum ;  ?/,  episternum  of  meta- 
thorax  ;  yf,  epimeron  of  metathorax  ; 
z,  mctasternum. 

1  '1  he  leader  should  run  to  base  of  labial 
palp,  d. 


FIG.  62&.  —  Upper 
surface  of  Necro- 
phorus,  a  carrion 
beetle.  After  Le  Conte.  a, 
mandible ;  6,  maxillary  palp ; 
c,  labrum1;  d,  epistome ;  e, 
antenna;  g.  vertex  of  head; 
h,  back  of  head;  i,  neck; 
^prothorax;  m,  elytron;  ??, 
wing  or  hind  wing ;  o,  scutel- 
lum  (of  mesothorax)  ;  p,  dor- 
sal surface  of  metathorax  ;  q, 
femur  or  thigh ;  r,  r2,  r3,  etc., 
dorsal  abdominal  segments; 
s,  s'2,  -s3,  etc.,  spiracle  openings 
or  stigmata;  t,  tf,  t  ',  tibise  ; 
v,  tibial  spurs;  w,  tarsi. 


1  The  leader  should  run  to  the  V-shaped  piece  in 
front  of  d. 


60 


ZOOLOGY 


c2.     Antennae   straight,  or,  if  bent,   not  ter- 
minating in  lamellate  club. 
di.    Maxillary  palp  as  long  as  or  longer 
than  antennae    . .    .. •    '-.-  '•    . 

dz'    Maxillary  palp  clearly  shorter  than 

antennae. 

e\.     Six  to  seven  ventral  segments, 
or  if  only  five,  the  first  3  or  4 
are  grown  together, 
/i.     Anterior  coxae  spherical  or 
transverse,        projecting 
little    from     the     coxal 
cavity. 

gi.  All  legs  used  in  run- 
ning or  walking  . 

g2.  At  least  the  hinder 
legs  used  for  swim- 
ming 

/2.  Anterior  coxae  conical  or 
tooth-like,  projecting 
prominently  from  coxal 
cavities. 

gi.  Anterior  coxae  coni- 
cal ;  abdomen  com- 
posed of  six  rings  . 

</2.  Anterior  coxae  ap- 
proximately cylin- 
drical ;  c  u  t  i  c  u  1  a 
soft,  leathery 

e2.     Abdomen  composed  of  five  rings, 
/i.     Anterior    coxae    spherical ; 
prothorax  with    a    pro- 
cess resting  in  a  depres- 
sion of  the  mesothorax. 
<7i.     Not  capable  of  leaping 
into  the  air 


.    Hydrophilidae, 

(Water-scavengers) 


CarabidfK 

(Runners) 

Dytiscidce 

(Divers) 

Gfyrinidce 
J    (Whirligigs) 


Silphidce 

(Carrion-beetles) 


Lampyridce 

(Fin-Hies) 


Buprestidce 


(Metallic  Wood-borers) 


APPENDIX  TO   CHAPTER  III  61 

g%.     Capable  of  leaping  into 

the  air      .         .         .          Elateridce 
(Click-beetles) 

/2.     Anterior  coxae  conical,  pro- 
truding from  coxal  cavi- 
ties       ....        Dermestidce 
(Dermestids) 
«o.     Hinder  tarsi    4-jointed ;    anterior    and    posterior 

tarsi,  5-jointed  [  Heteromera] . 
61.     Fore  coxae  separated,  more  or  less  enclosed  in 

coxal  cavity Tenebrionidce 

(Meal-beetles) 

?)»•     Fore  coxa3   near  together,  protruding ;    neck 
evident ;  elytra  broader  than  attachment  to 

thorax Meloidw 

(Blister-beetles) 

«3.     Tarsi  apparently  4-jointed,  really  5-jointed,  with 
very  small,  hidden,  penultimate  segment  [Cryp- 
topentamera] . 
61.     Head  drawn  out  into  proboscis        .       j     -  .    Curculionidce 

(Snout-beetles) 
&2-     Head  not  drawn  out  into  proboscis. 

GI.     Head    prominent ;    antennae    usually    as 

long  as  or  longer  than  body        .        .     Ccrambycidce 

(Long-horns) 

c2.     Head  short,  sunk  in  thorax. 

d\.     Antennae    short,    bent,    with    thick 

terminal  knob      .        .        ,         .  Scolytidw 

(Engravers) 

dz-     Antennas  thread-like  or  beaded        .    Chrysomelidce 

(Lea^-beetles) 

a±.  Hind  tarsi  apparently  3-jointed,  really  4-jointed, 
with  inconspicuous  penultimate  joint  [Crypto- 
tetramera] .  Short  head,  without  clearly  marked- 
off  thoracic  shield  .  .  .  .  '  .  -  -  .  Coccinellidce 

(Ladybirds) 


CHAPTER   IV 

THE   FLY  AND   ITS   ALLIES 

THE  term  "fly"  is  applied  to  many  of  the  insects  belong- 
ing to  the  Diptera1  or  group  of  two-winged  insects.2  It  is 
strictly  applied  to  the  family  Muscidse.3  The  most  gener- 
ally known  representatives  of  this  family  are  the  house-fly 
with  a  sucking  mouth,  the  stable-fly  with  a  mouth  fitted  for 
piercing  skin  and  sucking  blood,  and  the  blow-fly  with  a 
steel-blue  abdomen.  These  flies  love  sunshine  and  dryness. 
On  a  bright  day  they  fly  actively  in  the  open  air.  On 
damp  days,  on  the  other  hand,  they  swarm  into  houses  and 

1  8/j,  twice  ;  irrepbv,  wing. 

2  The  following  is  a  key  to  the  principal  suborders  of  the  Diptera  :  — 

«i.    All  three  thoracic  segments  fused,  usually  winged  ; 
under  lip  unsegmented. 

61.  Adults  not  parasitic  ;  maxillae  covered  by  upper 

lip. 
Ci.    Antennae  long,  many-jointed       .         .         .       Nematocera 

(Gnats  and  Midgets," 

C2-    Antennae  short,  usually  3-jointed  ;  the  third 

joint  ringed Brachycera 

(Flies) 

62.  Adults  parasitic  ;  upper  lip  enveloped  by  max- 

illae as  by  a  sheath Pupipara 

(Ex.  Sheep-tick) 
«2-    The  three  thoracic  segments  separate,  no  wings, 

under  lip  segmented     ...,.„      Aphaniptera 

(Fleas) 

3  musca,  fly. 

62 


THE  FLY  AND  ITS  ALLIES  63 

stables  to  avoid  the  wet,  and  otherwise  show  so  great  a 
sensitiveness  to  moisture  that  we  predict  rain  by  their 
stickiness  and  general  increased  ability  to  annoy.  Both 
the  house-fly  and  the  stable-fly  are  abundant  about  stables, 
where  their  eggs  are  laid,  and  also  about  household  pro- 
visions. 

The  different  species  of  flies  require  different  kinds  of 
food,  and  the  food  of  the  larvae  is  usually  different  from 
that  of  the  adult.  Thus  the  larva  of  the  house-fly  develops 
in  horse  manure  and  various  other  kinds  of  filth,  while  the 
adult  feeds  chiefly  upon  fluids  or  substances  which  can 
be  dissolved  by  their  saliva  and  then  sucked  up.  The 
larva  of  the  stable-fly  lives  in  and  feeds  upon  horse  manure. 
The  adult  sucks  blood.  The  larvae  of  the  blow-fly  develop 
in  meat,  cheese,  or  nitrogenous  vegetable  material. 

The  development  of  flies  is  rapid.  One  or  two  hundred 
eggs  may  be  laid  by  a  single  individual.  These,  in  warm 
weather,  hatch  in  a  few  hours  into  larvae,  commonly  called 
"  maggots."  The  larvae  are  wholly  footless,  and  even  the 
head  is  only  a  slightly  developed  structure.  The  larvae 
acquire  full  size  in  about  a  week ;  pupate  and  hatch  about 
a  week  later.  The  process  of  pupation  is  a  complicated 
one,  for  all  the  larval  organs,  excepting  certain  patches  of 
tissue,  are  destroyed.  By  the  growth  of  these  patches  the 
individual  is  formed  anew.  These  changes  are  all  deep 
lying,  and  nothing  seems  more  passive  than  the  brown 
pupal  case.  Finally  the  case  breaks  at  one  end,  and  the 
fully  formed  fly  emerges.  The  metamorphosis  which  the 
fly  has  just  undergone  is  a  complete  one. 

The  larvae  as  well  as  the  adult  flies  breathe,  like  other 
insects,  by  means  of  a  system  of  air-tubes,  which  begin 
with  slits  in  the  body  wall,  stigmata,  and  pass  inward  to 


64  ZOOLOGY 

all  parts  of  the  body  —  the  muscles  and  all  other  internal 
organs.  These  air-tubes  are  called  trachea.  They  can  be 
seen  best  in  some  aquatic  larvae  with  the  aid  of  a  strong 
magnifying-glass.  Air  is  driven  in  and  out  of  these  tubes 
by  means  of  expansions  and  contractions  of  the  body  wall. 

Although  so  very  numerous,  flies  would  be  still  greater 
pests  if  it  were  not  for  the  fact  that  they  are  preyed  upon 
by  various  parasitic  animals  and  plants.  The  larva  of  the 
house-fly  is  sometimes  infested  by  minute  hymenopterous 
parasites.  A  still  more  important  foe  is  a  minute  plant  — 
a  fungus  called  Empusa1  muscce^  —  which  infests  house- 
flies  in  the  autumn.  The  dead  flies  may  often  be  seen  on 
window  panes  with  fine  white  threads  sticking  out  of  the 
body,  and  surrounded  by  a  halo  made  up  of  the  spores 
discharged  from  the  fungus  upon  the  glass. 

The  order  Diptera  is  a  large  one  and  a  difficult  one  to 
study,  for  it  contains  many  species  and  many  of  the 
species  are  composed  of  small  individuals  which  are 
comparatively  unknown.  The  members  of  the  group  can 
usually  be  distinguished  by  having  only  two  wings,  the 
posterior  pair  being  rudimentary  and  transformed  into 
knobbed  "  balancers."  An  account  of  the  principal  fami- 
lies follows. 

The  short-horned  Diptera  (Brachycera3),  to  which  family 
the  house-fly  belongs,  includes  flies  in  which  the  third  seg- 
ment of  the  antennae  is  unsegmented,  called  true  Brachy- 
cera, and  flies  in  which  the  third  segment  of  the  antennae 
is  segmented,  called  anomalous  Brachycera.  The  true 
Brachycera  include,  besides  the  common  flies,  several 
other  common  or  especially  interesting  flies. 

,  a  hobgoblin.  2  Of  a  fly. 

,  short ;  fcepas,  horn  or  antenna. 


TEE  FLY  AND   ITS   ALLIES  65 

A  member  of  the  family  Muscidse,  which  is  especially 
destructive  in  tropical  Africa,  is  the  tsetse-fly  (Fig.  63). 
The  bite  of  this  fly  is  so  dangerous  that  horses  and  dogs 
cannot  penetrate  the  region  infested  by  it.  Even  herds  of 
cattle  may  be  killed  by  this  fly.  Consequently  travellers 
have  been  hindered  in  penetrating  into  this  country,  and 
the  opening  up  of  tropical  Africa  to  agriculture  and  com- 
merce has  been  much  interfered  with.  The  injurious 


FIG.  63. —  Glossina  moristans,  the  tsetse-fly.       FIG.  G4. —  Syrphus.      From 
From  the  "  Standard  Natural  History."  Packard. 

effect  of  the  bite  of  this  fly  is  due  to  a  parasite  introduced 
by  it  into  the  body  of  the  victim. 

Another  destructive  family  includes  the  bot-flies  ((Estii- 
dse1),  which  have  a  general  resemblance  to  honey-bees  or 
bumblebees.  Their  larvae  are  parasitic  in  mammals.  Of 
this  family  the  bot-fly  of  the  horse,  Grastrophilus2  equif  is 
the  most  generally  known.  These  flies  hover  about  the 
legs  of  horses  and  lay  their  eggs  upon  the  horse's  hair. 
The  larvaa,  irritating  the  horse's  skin,  are  licked  by  the 
horse  into  its  mouth  and  swallowed.  In  the  stomach  or 

,  gadfly.  2  yourr-ftp,  belly  ;  0i\«k>,  to  like.  3  Of  the  horse. 


66 


ZOOLOGY 


intestine  of  the  horse  they  get  abundant  food,  and  there 
they  develop.  The  larvae  of  another  species,  "  the  ox- 
warble "  or  "grubs,"  are  taken  into  the  mouth  of  cattle, 
and  live  for  a  time  in  the  oesophagus.  Then  they  bore 
their  way  through  the  walls  of  this  tube,  and  travel  on 
until  they  make  their  way  out  through  the  skin  to  the 
surface.  Another  injurious  species  is  the  sheep  bot-fly, 
whose  larvae  cause  "  staggers "  in  sheep. 

The  Syrphidae,1  like  the  bot-flies,  mimic  honey-bees, 
bumblebees,  and  wasps.2  The  adults  feed  on  the  pollen 
and  nectar  of  flowers,  and  even  imitate  the  humming  of 
the  bee.  The  larvae  of  some  forms  feed  upon  plant-lice ; 
others,  upon  decaying  vegetable  matter.  They  may  occupy 
the  nests  of  various  stinging  Hymenoptera.  The  larvae 
of  some  species  are  known  as  rat-tailed  maggots  on  account 

1    of   their   having  a  characteristic   append- 

l^jjjf  age.     These  are  sometimes  found  floating 

jHBMp**       iii  foul  water  or  even  in  salt  water. 

The  robber-flies  (Asilidae3)  are  usually 
jlHwl  °f  large  size,  have  a  short  head,  prominent 

eyes,  legs  covered    with    stiff    hairs,  and 
abdomen    either   long   and  slender    (Fig. 
- — — 1    65),  or  stout.     These  flies  attack  and  de- 
vour other  flies  and   even    insects    much 
larger  than   themselves,  such  as  bumble- 
bees and  dragon-flies. 
The  horse-flies  (Tabanidse4)  include  the  large  mourning 
horse-fly,  Tabanus  astratus,  which  is  of  a   uniform  black 
color,  the  white-lined  Tabanus,  T.  lineola  (Fig.  66),  and 
the  smaller  golden-headed  horse  and  ox  flies  with  banded 

1  cru/>06s  or  fftp<f>os,  a  small  winged  insect.  2  Fig.  64. 

8  From  asilus,  a  gadfly.  4  From  tabanus,  the  gadfly  of  Pliny. 


FIG.  65.— Robber- 
fly.  Nat.  size. 
Photo,  by  W.  H. 
C.  P. 


THE  FLY  AND   ITS  ALLIES 


67 


wings  (Fig.  67).  Only  the  female  sucks  blood,  while  the 
male  feeds  in  flowers.  They  are  powerful  and  rapid  fliers. 
The  larvae  are  carnivorous  and  live  in  the  earth  or  water. 


FIG.  GG. —  Tabanux  llmola,  white- 
lined  horse-fly.  X  1.2.  Photo,  by 
W.  H.  C.  P. 


FIG.  67.  —  Chrysops,   banded  horse- 
fly.   X  1.5.    Photo,  by  W.  H.  C.  P. 


The  black-flies  (Simuliidse  r)  are  representatives  of  the 
long-horned  flies  (Nematocera).  They  are  familiar  pests 
in  the  forests  of  our  Northern  country.  The  females,  which 
alone  suck  blood,  occur  in  such  num- 
bers and  are  so  active  that  they  render 
certain  places  almost  uninhabitable  to 
man.  Their  bite  often  produces  wide- 
spreading  and  painful  inflammation, 
accompanied  by  swelling  (Fig.  68). 
The  larvae  are  aquatic.  The  Southern 
black-fly  or  "  buffalo  gnat "  sometimes 
causes  the  death  of  domestic  animals. 

The  gall-gnats   (Cecidomyidse 2)  are 
minute  flies  which  lay  eggs  on  plants, 
their  way  into  the  plant  tissue,  and  cause  the  further  de- 
velopment of  the  tissue  to  be  abnormal,  so  that  excrescences 


FIG.  G8.—  Simulium, 
the  black-fly.  En- 
larged.  From 
Packard. 

The  larvae  make 


1  From  simul,  together  ;  or  simultas,  a  hostile  encounter. 

2  s,  gall-apple  ;  /tvta,  fly. 


68 


ZOOLOGY 


or  galls  are  produced.  The  galls  are  formed  only  in  grow- 
ing tissue  such  as  the  tips  of  branches,  buds  of  flowers  or 
growing  leaves,  and  are  less  striking  on  the  whole  than  the 
galls  of  Hemiptera  (Fig.  69).  A  certain  kind  of  gall-fly, 
called  Hessian-fly  (Fig.  70),  is  extremely  injurious  to  wheat 


FIG.  69.  —  Plant  galls  produced  by  Hemiptera  and  Diptera.  1.  Pine-apple  gall 
on  twigs  of  the  spruce  fir  produced  by  the  spruce-gall  Aphis  (C'herines 
abretis,  one  of  the  Hemiptera).  2.  Covering  gall  on  the  petiole  of  the  pyra- 
midal poplar  (Populus  pyramidalis) ,  produced  by  Pemphigus  bursarius, 
one  of  the  Hemiptera.  3.  Covering  galls  on  an  ash  leaf  (Fraxinus  excelsior) , 
produced  by  Diplosis  botularia  (Diptera).  4.  Covering  gall  on  Pistacia 
(Pistacia  lentiscus),  produced  by  Pemphigus  cornicularius.  5.  Solid  galls 
on  the  cortex  of  Duvana  lonyifolia,  produced  by  Cecidoses  eremite  (Hemip- 
tera) .  fi.  Longitudinal  section  of  one  of  these  galls.  7.  Capsule  galls  on  the 
leaf  of  the  turkey  oak  ( Quercus  cerris,  Hemiptera) ,  produced  by  Cecidomyia 
cerris.  8.  One  of  these  galls  cut  through,  with  the  operculum  still  firmly 
attached.  9.  The  same,  with  the  operculum  falling  away ;  X  3.  The  remain- 
ing figures  natural  size.  From  Kerner,  "  Pflanzen  Leben." 


THE  FLY  AND  ITS  ALLIES 


69 


FIG.  70.  —  Cecidomyia,  theHessian- 
tfy.  (/,  larva;  b,  pupa.  From 
the  "  Standard  Natural  History." 


because  it  infests  wheat  seedlings  and  so  weakens  them  that 
they  produce  no  grain.  Other  minute  gnats  or  midges 
are  destructive  to  clover  in 
the  United  States,  either  by 
binding  the  leaves  together 
and  sucking  the  sap  of  the 
destroying  the 


plant    or    by 

young  seed. 

The  mosquitoes,  or  Culicidse,1 

are  so  well  known   that    it  is 

hardly   necessary    to    describe 

them.      They    can    always   be 

identified  by  the  feathery  an- 

tennse,  by  the   presence    of   a 

fringe  of  hairs  on  the  hind  margin  of  the  wing,  and  by  the 

fact  that  the  marginal  vein  runs  all  around  the  periphery  of 

the  wing.  The  larvse  are 
usually  aquatic,  but  some 
species  which  are  abun- 
dant on  our  Western  arid 
plains  must  breed  in  the 
earth.  The  eggs  of  the 
aquatic  species  are  laid  in 
a  boat-shaped  mass,  which 
floats  on  the  surface  of  the 
water.  The  larvae  escape 

abdomen  with  the  two  oar-like  swim-     from  the  lower  ends  of  the 
ming  appendages,   dorsal  view.     After 
drawing  of  E.  Burgess. 


FIG.  71.  —  Culex,  the  mosquito.  A,  larva; 
c,  its  respiratory  tube.  B,  pupa ;  cl,  the 
respiratory  tubes;  a,  the  end  of  the 


egg-cases,  and  are  known 
as  "wigglers.'"    The  larvse 
rest  vertically  near  the  surface  of  the  water,  head  downward, 
with  the  tail  end  of  the  body  at  the  surface  of  the  water, 
1  Culex  was  Pliny's  name  for  the  fly. 


70 


ZOOLOGY 


since  respiration  takes  place  at  that  end  (Fig.  71,  A,  <?). 
Upon  emerging  from  the  water,  the  mosquito  floats  in  its 
pupal  skin  until  its  legs  and  wings  harden.  Since  a  dis- 
turbance in  the  water  at  this  time  would  jeopardize  the 
life  of  the  mosquito,  this  insect  always  breeds  in  quiet 
waters.  From  the  habits  of  the  larvse,  it  follows  that  they 
can  be  easily  killed  while  in  the  pond  by  pouring  kerosene 
oil  on  the  water,  for  this  forms  a  film  on  the  surface  and 


FIG.  72.  —  A  crane-fly.     Nat.  size.     Photo,  by  W.  H.  C.  P. 

prevents  respiration.  The  objection  to  this  treatment,  how- 
ever, is  that  most  of  the  other  aquatic  organisms  also  are 
killed  by  it. 

The  crane-flies  (Tipulidse 1)  look  like  mosquitoes,  but  can 
easily  be  distinguished  from  them  by  the  fact  that  they 
have  a  V-shaped  suture  on  the  back  of  the  thorax. 
They  are  larger,  and  have  relatively  longer  legs  than  the 


water, 


among   the   Latins   an  insect  which  courses  rapidly  on  the 
a  water-spider. 


THE  FLY  AND  ITS  ALLIES  71 

mosquito.  Their  legs  are  easily  broken,  and  seem  to  be  so 
much  in  the  way  that  flight  is  clumsy.  The  adults  are 
quite  harmless,  but  some  of  the  larvse  are  destructive  in 
that  they  feed  upon  tender  plants  and  cause  them  to  wither 
and  die. 

There  remain  to  be  considered  a  number  of  degenerate 
flies  —  degenerate  because  parasitic  in  the  adult  state.  The 
first  family  we  may  consider  is  that  of  the  louse-flies,1  or 
Hippoboscidae.2  These  small  insects  have  a  firm  proboscis 
used  for  piercing,  and  stout  legs.  Only  certain  of  the 
genera  develop  wings,  and  some  of  these  lose  them  after 
they  gain  their  hosts.  They  live,  like  lice,  in  the  fur  of 
mammals  or  the  feathers  of  birds.  They  are  viviparous, 
the  larvae  being  ready  to  pupate  at  the  time  of  birth.  The 
sheep-tick,  Melophayuz*  ovinusf  is  one  of  the  best-known 
forms.  Diptera  allied  to  the  foregoing  live  as  parasites 
on  the  body  of  the  honey-bee. 

Fleas  (Aphaniptera 5)  are  likewise  wingless,  blood-suck- 
ing parasites.  The  body  is  laterally  compressed  so  that  it 
can  move  easily  among  the  hairs  of  its  host.  The  hind- 
ermost'  legs  are  strongest,  and  are  used  in  springing.  In 
Europe  the  human  flea,  PulexQ  irritans?  is  a  common  pest, 
but  in  this  country  the  dog  or  cat  flea  is  the  one  which 
causes  most  inconvenience  to  man.  The  dog  flea  differs 
from  Pulex  irritans  in  having  a  row  of  tooth-like  spines  on 
the  lower  margin  of  the  head.  The  fleas  develop  in  dust 
in  the  cracks  of  the  floor  and  about  the  sleeping-places  of 
domestic  pets.  They  may  be  combated  by  means  of  clean- 
liness and  Persian  insect  powder. 

1  Suborder  Pupipara.  4  Relating  to  sheep  (ovis). 

2  IWos,  horse  ;  /360-Kw,  to  feed.  6  d0cu^s,  invisible  ;  Trrepdv,  wing. 

3  /jLrjXov,  sheep  (wool) ;  (j>dyw,  to  eat.       6  Flea.  7  Irritating. 


72  ZOOLOGY 

Diptera  affect  man  directly  in  very  diverse  ways. 
House-flies,  black-flies,  mosquitoes,  and  fleas  are  a  positive 
source  of  discomfort,  and  often  of  disease.  Thus  there  is  a 
minute  round  worm,  Filaria l  hominis?  allied  to  the  vinegar 
eel,  which  thrives  as  a  parasite  in  the  blood-vessels  of  men 
living  in  the  tropics.  The  existence  of  this  parasite,  it  is 
believed,  depends  upon  the  mosquito.  The  embryos  are 
found  in  the  surface  circulation  only  at  night,  during  which 
time  man  is  most  defenceless  toward  the  mosquito.  The 
embryos  of  the  Filaria  which  have  been  sucked  out  of  the 
blood  by  the  mosquito  develop  in  its  alimentary  tract,  later 
they  are  deposited  in  stagnant  water  with  the  eggs  of  the 
mosquito,  and  reach  man's  body  again  if  the  water  be 
drunk  by  him. 

It  is  a  current  scientific  belief  that  house-flies,  whose 
larval  stages  are  often  spent  in  filth,  which  also  the  egg- 
laying  females  visit,  are  an  important  agent  in  the  distribu- 
tion of  disease.  At  least  the  suspicion  is  strong  enough  to 
justify  all  care  taken  to  exclude  flies  from  contact  with  food. 

Indirectly  Diptera  are  injurious  to  man  by  attacking 
domestic  animals  and  cultivated  plants.  Thus  the  tsetse- 
fly  is  a  menace  to  the  commerce  of  a  large  part  of  a  conti- 
nent. The  horse-fly,  the  horn-fly,  which  worries  cattle,  the 
buffalo-gnat,  which  worries  or  even  kills  domestic  animals, 
and  the  dangerous  bot-fly,  are  all  causes  of  great  loss  to 
industry.  Also  we  have  seen  that  the  larvae  of  some  flies 
infest  vegetables, — such  as  cabbage,  radish,  cauliflower, 
onion,  —  as  well  as  various  fruits,  and  cause  great  damage. 
The  gall-gnats  destroy  clover  and  its  seed ;  and,  worst  of 
all,  the  Hessian-fly  infests  wheat  and  Indian  corn.  This 
last-named  scourge,  so  called  because  of  a  tradition  that  it 

1  filum,  thread.  2  Of  man. 


THE  FLY  AND  ITS  ALLIES  73 

was  imported  in  the  straw  bedding  of  the  troop-ships  which 
brought  over  the  Hessian  mercenaries  in  1775,  has  spread, 
within  a  century,  over  the  eastern  half  of  the  United  States, 
and  has  at  various  times  injured  the  wheat  crop  to  the 
value  of  millions  of  dollars.  The  larvae  of  certain  Muscidse, 
especially  the  genus  Chlorops,1  attack,  in  Europe,  the 
stems,  leaves,  and  ears  of  wheat,  rye,  and  barley,  and 
cause  in  some  years  great  destruction,  especially  in  Scan- 
dinavia. 

Over  against  the  injury  wrought  by  the  Diptera  may  be 
placed  certain  benefits  bestowed  by  them.  In  the  first  rank 
come  certain  species  which  prey  upon  injurious  insects, 
either  in  the  larval  or  adult  stage.  The  robber-flies  prey 
on  the  Diptera,  Hymenoptera,  and  certain  beetles,  but  they 
are  not  careful  to  choose  alone  injurious  species.  The 
larvae  of  the  Syrphidse  prey  on  the  injurious  plant-lice; 
those  of  horse-flies  are  carnivorous,  and  feed  on  insect  larvse. 
The  larvse  of  certain  small  flies  are  internal  parasites  of 
bugs,  beetles,  and  other  (mostly  injurious)  insects ;  while 
those  of  various  other  Diptera  are  useful  in  acting  as  scav- 
engers, —  mosquito  larvse,  for  example,  serve  in  this  way. 
The  carrion-fly  devours  putrid  animal  substances,  which 
might  otherwise  be  a  source  of  discomfort  or  disease.  The 
insects  which  feed  on  decaying  vegetable  matter  are  also 
not  to-be  despised.  Finally,  the  larvse  of  some  crane-flies, 
robber-flies,  and '  Syrphidse,  by  boring  into  rotten  wood, 
help  in  the  work  of  forming  forest  mould.  The  Diptera, 
like  almost  every  other  insect  group,  has  its  economically 
injurious  and  beneficial  species,  and  it  is  impossible  to  say 
whether  mankind  would  be  better  or  worse  off  were  the 
group  to  be  exterminated. 

green  ;  oty,  eye. 


CHAPTER  V 

LITHOBIUS   AND   ITS   ALLIES 

LITHOBIUS  is  a  representative  of  the  group  Myriapoda,1 
which  are  air-breathing,  wingless  Arthropods,  closely  allied 
to  insects.2  In  the  body  only  two  regions,  head  and  trunk, 
can  be  distinguished  ;  the  head  bears  one  pair  of  antennae, 
a  pair  of  jaws,  and  one  or  two  pairs  of  maxillae.  Every 
segment  bears  legs.  Myriapods  differ  from  insects,  then,  in 
that  they  have  no  legless  abdomen. 

Myriapods  fall  into  two  principal  groups,  —  Chilopoda  3 
and  Diplopoda.4 

The  chilopods,  or  centipedes,  to  which  group  Lithobius 
belongs,  are  active  and  ferocious  rnyriapods.  They  are 
especially  abundant  in  tropical  countries,  but  thrive  also  in 
elevated,  cold  situations,  and  at  least  one  species  inhabits 
the  caves  of  North  America.  All  are  terrestrial,  and  live 
in  damp  and  dark  places,  especially  under  stones  and 
bark,  within  or  under  decaying  wood,  among  barn-yard 
refuse,  in  loose  soil,  and  under  fallen  leaves.  Chilopods 
feed  upon  living  insects,  mollusks,  and  worms,  and  may  be 
useful  to  agriculture  through  the  destruction  of  injurious 


s,  very  many  ;  TTO^S,  foot. 

2  Keys  to  the  principal  families  of  the  Myriapoda,  and  to  the  commoner 
species  of  Lithobius,  will  be  found  at  the  end  of  the  Chapter,  page  78. 

3  More  correctly  Cheilopoda,  from  •^el\o<s^  lip,  and  TTO^S,  foot  ;  because 
the  mouth  parts  (modified  feet)  are  partially  united  to  form  a  sort  of  lip. 

4  SnrXoCs,  double  ;  Trotfs,  foot  ;  having  two  pairs  of  feet  to  the  segment. 

74 


LITHOBIUS  AND  ITS  ALLIES 


75 


insects.  Lithobius  has  been  observed  to  spend  hours  in 
killing  an  earthworm,  whose  juices  it  sucked  as  food. 
Blue-bottle  flies  also  serve  it  as  food  while  in  confinement. 

Lithobius1   is    of   world-wide 

distribution,  and 

over    one    hun: 

dred  species  are 

recognized.  Our 

common    straw- 
colored,  eastern 

species,      Litho- 
bius  forficatus? 

is  found  also  in 

South  America, 

as  well  as  over 

most  of  Europe. 

It  seems  to   be 

replaced     south 

of   Virginia    by 

another  species, 

spinipes. 

Scutigera 3    is 

easily    distin- 
guished  by    its 

.         J       .         FIG.   74.  —  Scolo- 
long     legs  ;      its        pendra.        Nat. 


FIG.  73.  —  Scutigera.     Nat.  size 
From  Wood. 


111- 


size.       From 
Leunis. 


lii  nd    legs, 

deed,  are  longer 
than  its  trunk.4  Our  common  Eastern  species  (rare  north 
of  New  York  City)  is  about  25  centimetres  long,  and  is 
of  a  light  brown  color,  with  stripes  on  the  back.  It  is 


1  \t0os,  stone  ;  ^3i6w,  to  live. 

3  scutum,  shield  ;  gerere,  to  bear. 


2  Provided  with  shears,  forfex. 
4  Fig.  73. 


76 


ZOOLOGY 


very  active,  and  feeds  especially  on  spiders.  It  looks  some- 
thing like  a  spider  itself  when  in  rapid  movement.  The 
Scutigeras  are  characteristic  of  the  tropics,  where  they  live 
especially  in  cellars,  crawling  up  horizontal  walls. 

Scolopendra 1  includes  longer  and  stouter  myriapods  than 
Lithobius.2  To  this  genus  belong  the  poisonous  centipedes 
of  tropical  countries.  Among  these  is  the  giant  Scolo- 
pendra of  our  Southern  States,  South  America,  and  the 
West  Indies,  which  reaches  a  length  of  25  centimetres 
or  more.  This  animal  has  a  poisonous  bite,  which  is 
fatal  to  insects  and  other  small  animals,  and  causes  pain- 
ful and  even  dangerous  wounds  upon  man.  The  biting 
apparatus  is  the  first  pair  of  feet,  modified  to  form  sharp 
hooks,  and  provided  with  poison-glands, 
which  open  near  the  apex  of  the  claw.  Ac- 
cording to  Humboldt,  the  Indian  children  of 
South  America  tear  off  the  heads  of  large 
centipedes  and  eat  the  remaining  portions. 

Geophilus8  includes  relatively  slow-moving 
species,  often  attaining  great  length,  having 
up  to  two  hundred  segments  to  the  trunk 
(Fig.  75).  The  species  are  common  in 
Europe  and  America.  They  live  mostly 
under  stones.  There  is  a  European  species, 
Cieophilus  electricus,  which  is  phosphorescent, 
shining  in  the  dark  like  a  glow-fly. 

Julus 4  is  very  different  in  appearance  from 
the  preceding,  for  it  has  a  cylindrical  body 
and  numerous  small  legs  nearly   concealed 
beneath  it.      It  is   commonly  known    as   "  galley-worm." 


FIG.  75.—  Geo- 
philus mor- 
dax.  Nat. 
size.  Photo. 
byW.H.C.P. 


<rKo\6Trevdpa,  myriapod  of  Aristotle. 


3  777,  the  earth  ;  0i\^w,  to  love. 

4  tovXos,  centipede. 


LITHOBIUS  AND  ITS  ALLIES 


11 


The  members  of  this  genus  crawl  rather  slowly,  and 
when  at  rest  coil  the  body.  When  disturbed  they  give 
out  a  strong  odor  through  lateral  open- 
ings of  the  body.  They  feed  on  dead 
snails  and  earthworms ;  some  species, 
on  ears  of  Indian  corn  or  strawberries. 
Their  eggs  are  laid  in  holes  in  the  „  _,. 

oo  FIG.  7b.  —  Jtilus  cana- 

ground  in  the  spring  ;  consequently  densis.  Nat.  size, 
they  may  be  easily  dug  up  at  this  P^oto.  by  W.H.C.P. 
season.  One  of  the  common  Eastern  species  of  North 
America  is  Julus  (^Parajulus)  canadensis,  which  is  dark 
brown  or  black  above,  has  sides  spotted  with  yellow,  and 
nearly  colorless  feet,  and  is  about  20  to  25  millimetres 
long  (Fig.  76).  Spirobolus  is  a  large 
species,  10  to  12  centimetres  long. 

Polydesmus l  includes  much-flattened 
species,  which,  when  disturbed,  roll  up 
spirally.  P.  canadensis,  of  the  northern 
United  States,  is  deep  brown,  with 
pubescent  antennae.  These  myriapods 
are  somewhat  destructive  to  agricul- 
ture, especially  to  cabbage  and  straw- 
berries. 

Two  genera  of  myriapods  which 
stand  somewhat  isolated  deserve  a 


FIG.    77.  —  Polydesmus  „ 

canadensis  (=  P.  serra-  passing  notice,     rauropus  J  and  allied 

W°H  c1?'   Photo>by  genera   include    a   few  animals   about 

1  millimetre  long,  found  on  the  moist 

loam  of  woods.     They  are  intermediate  between  chilopods 

and  diplopods,  inasmuch  as  they  have  only  one  pair  of  legs 


1  7roXi/5e0-/ios  :   TroAtfs,  much  ;  5eo>i6s,  band. 

2  Traupos,  small  ;  TTO^S,  foot. 


78 


ZOOLOGY 


to  a  segment  and  only  one  pair  of  maxillre.  P.  huxleyi 
occurs  both  in  Europe  and  in  the  United  States  (vicinity 
of  Boston  and  Philadelphia).  Scolopendrella 1  is  a  small, 
white  species,  having  very  large  antennae  and  a  pair  of 
backward-directed  stylets.  The  mouth  parts  are  very  much 
like  those  of  the  lowest  insects,  so  that  Scolopendrella 
bridges  the  gap  between  myriapods  and  true  insects. 


APPENDIX   TO   CHAPTER   V 


KEY    TO    THE    PRINCIPAL    FAMILIES    OF    THE    MYRIAPODA 


a\.  Not  more  than  1  pair  of  feet  to  the  segment ; 
much  segmented  antennae  ;  2  pairs  of  maxillae 
[Chilopoda]. 

61.     With  facetted  eyes ;  8  dorsal  plates ;  long 
legs  .       ,.-•-..        •      '  -.        •         • 

bo.     No  facetted  eyes,  but  single  or  aggregated 

simple  eyes  ;  15  or  more  dorsal  plates. 
ci.     15  pairs  of  legs  ;  antennae  at  least  £  as 
long  as  body ;    body  usually   with 
more  than  20  segments 

Ci.     More  than  21  pairs  of  legs. 

d\.     21  to  23  pairs  of  legs ;    antennae 
more  than  14-jointed 


d-2.     Never  less  than  30  pairs  of  legs  ; 
antennae  14-jointed   .       • .        . 

Most  of  the  segments  with  2  pairs  of  legs  ;  an- 
tennae with  5  to  8  segments  ;  1  pair  of  maxillae 
[Diplopoda]. 

61.  Anus  in  penultimate  segment ;  body  covered 
with  bunches  of  hairs  .  .  "  .  . 


Scutigeridce 

(Ex.  Scutigera) 


LithobiidcB 
(Ex.  Lithobius) 


Scolopendridce 

(Ex.  Scolopendra) 

Greophilidce 

(Ex.  Geophilus) 


PolyxeniddB 


1  Diminutive  of  Scolopendra. 


APPENDIX  TO   CHAPTER    V  79 

Anus  in  ultimate  segment;  body  without 

bunches  of  hairs. 
Ci.     Mandibles   not   rudimentary ;     mouth 

parts  not  suctorial. 
d\.     Segments  30  or  more. 

e\.     Anal  segment  produced  into 

a  spine       ....  Julidce 

(Ex.  Julus) 

62-     Anal  segments  produced  into 
2  slender  papillae,  or  uni- 
dentate       ....   Craspedosomidm 
dz.     Segments  19  or  20         .         .         .         Polydesmidce 

(Ex.  Polydesmus) 
C2.     Mandibles  rudimentary,  mouth  parts 

reduced .-         Polyzoniidce 


KEY    TO    COMMONER    SPECIES    OF    THE    GENUS    LITHOBIUS 

ai.     Posterior  angles  of  none  of  dorsal  plates  pro- 
duced ;  pores  on  coxae  uniseriate. 
b\.     A nal  feet  armed  with  1  spine ;  posterior  coxae 
unarmed  ;  spines  of  first  pair  of  feet,  2,  2, 
2-2,  3,  2  (Central  States)         .        .        .  bilabiatus 

62.  Anal  feet  armed  with  3  spines  ;  coxae  with 
indistinct  spine  ;  spines  of  first  pair  feet, 
2,  3,  2  (Central  States)  .  .  .  '  _.:  cardinalis 

«2-     Posterior  angle  of  the  9,  11,  13  dorsal  plates  pro- 
duced; antennae,  33-43  joints  (eastern  U.S.)  forficatus 
«3.    Posterior  angle  of  the  7,  9,  11,  13  dorsal  plates 
produced  ;  31-38  joints  of  antennas  (southern 
U.S.)        .        .        .        .        ,        .        .        .  spinipes 
«4.     Posterior  angle  of  the  6,  7,  9,  11,  13  dorsal  plates 
produced  ;  joints  of  antennae,  14-23  (eastern 
U.S.)       .        «        .        .                 .        .        .       multidentatus 


CHAPTER  VI 

THE   SPIDER   AND   ITS   ALLIES 

SPIDERS  constitute  a  well-defined  group  called  Araneina,1 
characterized  by  an  unsegmented  cephalothorax  and  abdo- 
men, of  which  the  latter  is  stalked,  and  bears  spinning 
tubercles  or  spinnerets  upon  its  hinder  end.  Antennae 
are  absent.  The  first  pair  of  mouth  appendages  are  called 
chelicerse  and  end  in  claws,  at  whose  apices  the  poison- 
glands  open  to  the  exterior.  The  second  pair  of  mouth 
parts,  called  pedipulps,  are  long,  and  seem  to  take  the 
place  of  antennae.  Near  the  stalk  of  the  abdomen  on  the 
ventral  side  is  a  pair  of  slits  which  open  into  two  lung 
sacks  (hence  Dipneumones).  In  a  few  spiders  there  is  a 
second  pair  of  slits ;  these  spiders  have  four  lung  sacs 
(hence  Tetrapneumones).2 

The  best  known  of  our  spiders  are  the  orb  web-spinning 
garden  spiders,  belonging  chiefly  to  the  genera  Epiera3 
or  Argiope 4  and  the  house  cobweb  spinning  spider 
Theridium.5 

Argiope  spins  webs  of  very  geometric  form  between 
stems  of  weeds,  branches  of  shrubs,  or  along  fences  in 
our  meadows.6  Its  web  belongs  to  the  full-orb  type  in 

1  aranea,  spider. 

2  A  key  to  the  seven  subdivisions  of  the  Araneina  will  be  found  at  the 
end  of  this  Chapter,  page  95. 

3  efjureipos,  skilful,  experienced. 

4  Name  of  a  nymph.          6  0rjpl5iov,  a  little  wild  animal.  6  Fig.  78. 

80 


THE   SPIDER   AND   ITS   ALLIES 


81 


contrast  to  the  condition  in  other  orb-spinners,  in  which 
a  sector  of  the  circle  is  omitted  or  in  which  a  sector  only 
is  formed.  At  the  centre  of  the  web  of  Argiope  there  is 
an  oval,  closely  woven  shield  of  silk.  The  spider,  when  at 
rest,  is  usually  found  upon  or  under  this  shield.  Another 
frequent  character  of  the  web  is  a  zigzag  ribbon,,  extending 


FIG.  78.  —  Web  of  Argiope,  placed  horizontally  over  a  fish-way.     Photo, 
by  W.  H.  C.  P. 


downward  from  the  central  shield,  and  sometimes  upward 
also,  and  attached  to  two  or  more  radii.  This  zigzag, 
which  is  doubtless  the  "  winding  stair "  referred  to  in 
the  rhyme,  "  The  Spider  and  the  Fly,"  is  formed,  as  Fig. 
79  shows,  by  preventing  the  fusion  of  the  strands  as  they 
emerge  from  the  spinnerets. 


82 


ZOOLOGY 


The  genus  Theridium  and  its  allied  genera  constitute  the 
most  extensive  family  found  in  the  United  States.  The 
spiders  belonging  to  the  family  are  small,  with  relatively 
large,  rounded  abdomens.  They  have  eight  eyes,  arranged 
in  the  manner  shown  in  the  diagram,  Fig.  80.  Their  webs 

show  no  attempt  at 
geometric  arrangement, 
such  as  is  seen  in  the 
web  of  Argiope  and 
other  orb-weavers,  but 
the  threads  cross  in 
every  direction,  forming 
a  sort  of  intricate  trestle- 
work.  The  species 
Theridium  tepidariorum 
is  the  common  little 
cobweb-spinner  of  our 
houses  and  barns  ;  it  also 
spins  about  fences.  Its 
color  varies  from  a  livid 
white  to  a  livid  brown 
or  plumbeous  color.  In 


the    south   this    species 

FHJ.  79.  — Argiope  spinning  the  "winding    . 

stair."    The  numbers  1,  2,  3,  4,  indicate    IS     much     preyed     upon 
points  successively  formed  in  the  order  of 
these  numerals.     From  McCook. 


^y    mud-daubing    wasps 
J  P 

(Sphex  J),  which  put 
twenty  to  thirty  of  them  in  each  cell  of  the  nest  as 
food  for  the  young.  Probably  this  enemy  is  one  of  the 
causes  that  has  driven  this  species  to  the  homes  of  man. 

Food.  —  Both  Argiope  and  Theridium  feed  upon  insects. 
Flies,  bees,  grasshoppers,  etc.,  are  caught  in  the  web  and 

1  <r<t>if]Z,  wasp. 


THE  SPIDER  AND  ITS  ALLIES  83 

bound  up,  either  for  immediate  or  future  consumption.     A 
few  authentic  instances  have  been  recorded  of  the  capture 
of  mice  by  ordinary  spiders,  and  some  tropical     0     o    o     o 
spiders  are  said  to  capture  occasionally  small          0     0 
birds   within    their   Avebs.      All   spiders   eat    FIG.  so.  — Dia- 

,  ,.         .  ,    .    ,  gram  of  posi- 

voraciously,  and  ordinarily  drink  a  great  thmof eyesm 
deal  of  water;  yet  they  may  survive,  in  Theridium. 

•J  J  The  four  cen- 

the  absence  of  food  and  water,  for  many  trai  eyes  are 
months.  the  larsest- 

Distribution.  —  Argiope  occurs  over  all  of  North  America. 
A.  cophinaria,  the  basket  Argiope,  is  the  large  black  and 
yellow  spider  well  known  to  all  frequenters  of  fields.  It 
occurs  from  Massachusetts  to  Texas,  and  west  to  the  Pacific 
coast.  A.  argentata,  distinguished  by  the  serrated  form  of 
the  abdomen,  is  found  in  the  Southern  States,  the  West 
Indies,  and  northern  South  America.  Theridium  occurs 
all  over  the  world.  T.  tepidariorum  is  found,  outside  of  the 
United  States,  in  South  America,  Europe,  and  Australia. 
Twelve  other  species  of  this  genus  are  found  in  New 
England  alone.  Some  of  these  spin  webs  in  trees  or 
bushes,  others  in  stone  walls  or  among  rocks. 

Spinning  Habits.  —  Spiders  spin  for  a  variety  of  purposes. 
Cocoons  are  made  of  silk,  for  the  protection  of  eggs  ;  under- 
ground nests,  like  that  of  the  trap-door  spider,  are  lined 
with  silk ;  and,  especially,  nets  are  made  of  it  to  ensnare 
insects.  The  silky  threads  may  serve  also  to  suspend  the 
spider  while  it  drops  from  a  tree,  or  they  may,  by  their 
friction  with  the  air,  serve  to  suspend  certain  spiders  in 
aerial  migrations.1  This  latter  use  is  especially  noteworthy. 

1  The  ballooning  habit  of  spiders  has  been  noticed  since  early  times, 
but  it  was  formerly  misinterpreted.  Thus  Pliny  speaks  of  wool  being 
rained.  The  poet  Spenser  wrote  :  — 


84 


ZOOLOGY 


A  small  spider,  when  desirous  of  taking  flight,  climbs  up 
some  high  object,  such  as  a  fence  post,  elevates  the  spin- 
nerets, and  spins  loose  silk  into  the  air  (Fig.  81).  After 
enough  of  it  has  been  thus  formed,  the  spider  lets  go,  and 
is  supported  by  the  currents  in  the  air  while  it  is  wafted 
great  distances.  Thus  Darwin,  on  his  voyage  in  the 
Beagle,  saw  cobwebs  bearing  up  spiders  floating  in  the 

air  over  his  vessel  more  than 
sixty  miles  from  shore. 

The  method  of  spinning 
deserves  careful  attention. 
The  spinning-organs  consist 
of  a  set  of  glands  lying  in  the 
hinder  part  of  the  abdomen, 
and  opening  to  the  exterior 
through  a  number  — -  often 
several  hundred  —  of  spin- 
ning "spools."  These  spools 
are  the  modified  mouths  of 
glands,  and  are  grouped 
upon  and  between  tubercles 
called  spinnerets.  The 
secretions  of  the  glands,  as 
they  are  poured  out  into 
the  air,  fuse  together  and 

harden  into  a  thread.  The  thickness  of  the  thread  is 
determined  by  the  number  of  glands  secreting  together. 

"  More  subtle  web  Arachne  cannot  spin  ; 
Nor  the  fine  nets,  which  oft  we  woven  see, 
Of  scorched  dew,  do  not  in  th'  ayre  more  lightly  flee." 
Thompson  writes :  — 

"  How  still  the  breeze  !  save  what  the  filmy  threads 
Of  dew  evaporate  brushes  from  the  plain." 


THE  SPIDEE   AND  ITS   ALLIES  85 

Classification.  —  Spiders  are  separated,  according  as  they 
spin  webs  or  do  not  do  so,  into  two  main  groups,  sedentary 
and  wandering  spiders.  The  sedentary  spiders  are  sub- 
divided into  four  sub-orders,  which  we  shall  consider  in 
turn :  — 


FIG.  82.  —  Mygale,  a  Tunnel-weaver,  allied  to  the  "  trap-door  spider." 
Nat.  size.     From  Emerton. 


1.  Tunnel-weavers  (Temtelariee  l) .  These  spiders  make 
tubes  in  the  earth,  and  line  them  with  silk.  The  repre- 
sentatives of  this  group  in  the  Southwestern  States  are 

1  terra,  earth  ;  tela,  tissue  or  web. 


86 


ZOOLOGY 


FS 


FS 


commonly  known  as  trap-door  spiders.  The  lid  of  the 
nest  is  covered  with  hardened  dirt,  and  when  closed,  looks 

exactly  like  the  ground  around 
it.  Some  of  these  spiders  gain 
a  great  size  and  capture  birds 
(Fig.  82). 

2.  Orb-weavers  (Orbite- 
larise 1).  These,  which  are 
typically  represented  by 
Argiope,  are  well  known ;  yet 
few  persons  have  studied  the 
almost  mathematical  precision 
with  which  the  webs  are  built. 

FIG.   83. -Diagram   on   nomencla-  Foundation     lines      (Fig.     83) 

tare  of  parts  of  an  orb-web.    FS,  of    UllUSUal   strength    are    tirst 

foundation     space ;     SS,     spiral  ,    .  ,    ,  ,.  , ,  .    , 

space;    OS,   central  space  ;    FZ,  laid  down'  to  ioi>m  the  penpll- 

freezone;  NZ,  notched  zone;  H,  eiy  or  frame  of  the  Web.     Then 
centre.     From  McCook.  ,..  . 

radii  are  spun  from  a  central 

little  ball  of  floss  to  the  frame.  The  radii  are,  often  at 
least,  laid  down  alternately  on  opposite  sides  of  the 
centre.  The  number  of  radii  formed  by  a  species  of 
spider  is  not  perfectly  constant,  but  varies  within  limits. 
It  would  be  an  interesting  occupation  to  sketch  a  number 
of  webs  of  Argiope  showing  the  variations  in  the  number 
of  radii  and  the  other  details  of  form.  After  the  radii  are 
placed,  the  spiral  lines  are  laid  down.  In  the  completed 
web  four  regions  are  distinguishable,  as  follows,  passing 
from  the  centre  outward :  (1)  the  notched  zone,  consist- 
ing of  four  to  eight  turns  of  a  spiral  at  the  centre ;  (2) 
the  free  zone  in  which  no  spiral  is  laid  down ;  (3)  the 
spiral  space,  the  main  part  of  the  spiral  framework  ;  (4)  the 

1  orbis,  circle  ;  tela,  web. 


THE  SPIDER   AND  ITS  ALLIES  87 

foundation  space,  without  the  spiral  lines,  and  at  the  outer 
margin  of  the  web.  No  study  is  more  interesting  than 
that  of  the  details  of  construction  of  these  parts  of  the 
spider  web,  while  they  are  being  made  out  of  doors  or  in 
large  glass  jars. 


FIG.  8-1.  —  Orb-web  of  Epeira.     a,  first  spiral  line ;  b,  second  spiral  line  ;  c,  line 
to  nest.     From  Emerton. 

3.  Line- weavers  (Retitelarise1).  —  Of  this  group  The- 
ridium  is  a  type.  The  web  consists  of  a  fine  irregular  mesh 
with  strands  running  above  and  below  in  various  direc- 
tions.2 The  spider  stands  below  the  main  part  of  the  net, 
back  downward. 

1  rete,  net ;  tela,  web.  2  Fig.  85. 


88 


ZOOLOGY 


4.  Tube- weavers  (Tubitelaricti  1).  --  Here  belong  the 
spiders  that  spin  webs  in  the  grass,  which  are  so  conspicuous 
in  the  morning  when  laden  with  dew  (Fig.  86).  At  one 
side  of  the  web  a  tube  leads  down  among  the  grass  stems. 
At  the  opening  of  this  tube  the  spider  stands  ready  to 


FIG.  85.  —  Web  of  Theridium,  a  "  cobweb."    From  Emerton. 

dart   out  after  prey,  or  to  retreat  as  occasion    demands 
(Fig.  87). 

The  wandering  spiders  do  not  spin  webs  of  any  kind. 
They  are  classified  into  three  groups  as  follows :  — 
1  tubus,  tube  ;  tela^  web. 


THE  SPIDER  AND   ITS  ALLIES 


89 


(1)  Crab  spiders  (Laterigradse  *)  are  so  called  because 
they  run  sideways.    They  make  nests  by  fastening  together 
leaves  by  threads  of  silk.     Their  young  are  reared  in  these 
nests,  and  watched  over  by  the  mother  (Fig.  88). 

(2)  Running  spiders  (Citigradse2). —  These  are  for  the 
most  part  large  and  powerful  species  which  wander  over 


FIG.  86. —  Web  of  a  tube-weaver;  looking  down  upon  the  web,  which  is  in  a 
corner  between  two  vertical  walls.  The  tube  is  in  the  angle.  Photo,  by 
W.  H.  C.  P. 


fields  or  along  watercourses  in  search  of  prey.  Our 
Northern  species  belong  chiefly  to  the  genus  Lycosa  3  (Fig. 
89).  They  live  in  holes  in  the  ground,  making  a  ring  of 
silk  at  the  orifice.  The  female  carries  her  eggs  about  in 
a  special  cocoon  attached  to  the  end  of  the  abdomen.  The 


1  latus,  side  ;  gradus,  locomotion. 

3  Xikos,  wolf. 


2  citus,  rapid,  +  gradi 


90 


ZOOLOGY 


FIG.  87.  — Agalena,  the  common 
grass  spider.  Nat.  size.  Photo, 
by  W.  H.  C.  P. 


young  are  borne  on  the  back  of 
the  mother.  The  great  size, 
black  color,  and  hairiness  of 
some  of  these  spiders  have  given 
them  an  apparently  unjustified 
reputation  of  being  very  poison- 
ous. Naturalists  who  have  al- 
lowed these  spiders  to  bite  the 
hand  report  that  the  bite  is  rarely 
more  poisonous  than  that  of  the 
mosquito. 

(3)  Jumping  spiders  (Salti- 
gradse *).  —  This  family  includes 
many  familiar,  active  species  of 

high  intelligence.  Some  of  these  of  grayish  color  live  in 
houses,  and  are  recognized 
as  members  of  this  family 
by  their  half-running,  half- 
jumping  gait  (Fig.  90). 
The  cocoon  is  attached  to 
some  object  and  enclosed 
in  a  sort  of  tent,  in  which 
the  mother  also  lives  to 
guard  the  young. 

The  economic  impor- 
tance of  spider  webs  is  con- 
siderable. First  of  all, 
they  are  of  the  greatest 
importance  in  capturing 
many  destructive  insects, 
such  as  flies,  mosquitoes, 
and  moths.  Another  use 

1  saltus,  jumping,  +  gradus. 


0    o     o    ° 

0     o        o     ° 

FIG.  88.  — Thotnisus,  a  crab  spider.  Dia- 
gram showing  arrangement  of  eyes  at 
bottom  of  figure.  From  Emerton. 


THE  SPIDER  AND  ITS  ALLIES  91 

to  which  they  have  been  put  is  in  making  silk  cloth.  The 
silk  of  the  spider  is  smoother  and  glossier  than  that  of  the 
silk-worm,  but  it  is  much  harder  to  collect  in  quantity. 
A  spool  is  passed  against  the  spinnerets  of  an  individual 
spider  and  slowly  revolved,  winding  the  silk  upon  it. 
The  difficulty  comes  in  rearing  the  spiders,  for  they  are 
extremely  voracious  and  if  the  supply  of  flies  is  insufficient 


FIG.   89.  — Lycosa,a  running  spider.        FIG.  (JO.  — Attus,  a  jumping  spider. 
Ocelli  formula  below.    From  Emer-  From  Emerton. 

ton. 

they  attack  and  devour  one  another.  Consequently  they 
must  be  kept  isolated  and  fed  individually,  and  yet  yield 
in  the  end  only  an  ounce  or  so  (about  30  grammes)  of 
silk.  Other  uses  of  spiders'  silk  are  :  in  the  construction 
of  cross-hairs  in  telescopes,  and  in  medicine  as  a  narcotic 
in  case  of  fevers,  —  a  temporary  fad. 

Poisonous  Spiders.  —  Spiders  are  feared  by  many  people 
from  a  belief  that  they  are  very  poisonous,  even  fatally  so. 
Spiders  have,  indeed,  biting  jaws  provided  with  poison- 


92  ZOOLOGY 

glands,  and  their  bite  is  often  fatal  to  insects,  and  even  to 
small  birds  and  mammals.  But  most  spiders  cannot  spread 
the  chelicerse  sufficiently  to  make  a  bite  in  the  human  skin, 
and  even  the  largest  forms  seem  to  inflict  but  a  slight 
wound,  scarcely  ever  greater  than  that  of  a  mosquito. 
The  stories  of  the  severe  effects  of  the  bite  of  the  Taran- 
tula, one  of  the  Lycosidae,  are  entirely  fabulous. 

Spiders  show  a  marked  sexual  dimorphism.  Particularly 
among  the  orb-weavers  the  males  are  much  smaller  than 
the  females  of  the  same  species,  but  the  legs  of  the  male 
are  relatively  the  longer  and  stronger.  The  male  is  usually 
shorter  lived  than  the  female,  for  the  latter  has  often  to 
watch  the  egg-cocoons,  or  carry  them  about  with  her  until 
the  young  hatch  out.  The  male  also  builds  less  perfect 
webs  than  the  female.  The  relation  existing  between 
mated  pairs  is  often  peculiar.  The  male  is  frequently 
killed  and  eaten  by  the  female;  but  if  the  male  can  over- 
come the  female,  she  may  fall  his  victim.  Among  wander- 
ing spiders  there  is  often  a  selection  by  the  female  from 
among  several  rivals,  which  engage  in  severe  battles  with 
each  other. 

Allies  of  the  spider  must  be  briefly  mentioned.  The 
spider  belongs  to  the  class  Arachnoidea,1  characterized  as 
follows:  Air-breathing,  wingless  arthropods,  whose  head 
and  thorax  are  usually  united  to  form  a  cephalothorax, 
which  bears  two  pairs  of  jaws  and  four  pairs  of  legs  ;  the  ab- 
domen, which  is  not  always  separated  from  the  cephalo- 
thorax, possesses  no  legs.  The  principal  subdivisions  of 
the  Arachnoidea  are  as  follows :  — 

The  Arthrogastra,2  including  the  scorpions  and  their 
allies,  are  characterized  by  the  fact  that  the  abdomen  is 

,  spider  ;  elSos,  form.  2  dpdpov,  joint ;  yaarr^p,  abdomen. 


THE  SPIDER  AND  ITS  ALLIES 


93 


segmented  and  intimately  joined  with  the  cephalothorax.1 
Here  belong  the  true  scorpions,  in  which  the  posterior  six 
segments  of  the  abdomen  are  much  smaller  in  diameter 
than  the  seven  anterior  segments,  and  form  a  sort  of  tail 
(post-abdomen).  Nearly 
twenty  species  of  scor- 
pions occur  in  the 
warmer  parts  of  North 
America.  Centrums  in- 
famatus  ranges  from  the 
southern  Atlantic  States, 
through  Texas,  and 
north  into  southern  Kan- 
sas. The  tip  of  the  tail 
bears  a  sting,  which  con- 
nects with  a  poison -sac. 
The  largest  scorpions 
of  the  tropical  countries 
are  the  most  dangerous, 
but  the  wounds  even  of 
these  are  rarely  fatal. 

The  Phalangina,2  the 
extremely  common 
"Daddy-long-legs,"  or 
harvest-men,  in  which 

the  legs    are  very    long,  FlG    9i._Buthus,    a    European    scorpion. 

and   the    abdomen   short  Dorsal  view.     MX.,  maxillary;    Cephth., 

i  •    i          T<U  cephalothorax;  Troch.,  trochanter ;  Tars., 

and  thick.       1  hey  OCCUr  tarsus .  Abd^  abdomen  ;  Bla.,  poison  blad- 

about   houses,  ill  woods,  der!  St.,  sting.    From  Kraepelin  in  "  Das 

,       .         „    ,  ,             rri^  Tierreich." 

and    in    fields.       They 

feed  on  small  insects  and  are  highly  beneficial  animals  to 
1  Fig.  91.  2  <j>a\dyyiov,  a  spider,  especially  a  poisonous  species. 


94 


ZOOLOGY 


FIG.  92.  —  Liobunum  dorsatum,  one  of  the  harvestmen.  The  long  legs  are 
apt  to  be  thrown  off  in  handling  the  living  animal.  The  second  left  leg  is 
accordingly  absent  in  this  specimen.  Nat.  size.  Photo,  by  W.  H.  C.  P. 


FIG.  93.  —  Psoroptes,  the  sheep  scab,  female.  IJight  figure,  dorsal  view  ;  left 
figure,  ventral.  Much  enlarged.  After  Salmon,  Bulletin  21,  Bureau  Animal 
Industry. 


THE  SPJTtE-R  ANX>  ITS  ALLIES  95 

man.  Liobunum  dorsatum  is  a  common  grayisli  species 
with  a  darker  dorsal  band,  which  emits  a  clear  fluid  when 
handled  (Fig.  92). 

The  Areneina,  or  spiders,  already  considered. 

The  Acarina,1  or  mites  and  ticks,  in  which,  as  in  spiders, 
the  abdomen  is  unsegmented,  but  is  fused  with  the  cephalo- 
thorax.  Mites  have  typically  a  round  body.  They  exhibit 
great  diversity  of  form  and  habits.  All  are 
terrestrial,  excepting  one  group  of  aquatic 
mites,  and  are  often  of  a  bright  red  color 
(Atax).  The  free-living  species  prey  on 
smaller  animals,  as  well  as  dead  organic 
substances.  Others  are  parasitic  in  animals 
or  plants,  living  in  fur  or  feathers,2  and  even  jjne  "  ~ 


a   sea- 


penetrating  into  the  skin,  as  the  small  red  -  spider,  x  1.5. 
44  jigger"  or  "  chigger  "  of  our  Southern  fc^'aSS 
States  does. 

Finally,  there  lives  in  the  sea  an  aberrant  family  of 
spiders  which  crawl  on  the  sea-bottom  or  over  hydroids, 
and  thus  have  forsaken  a  terrestrial  life  for  a  completely 
aquatic  one  (Fig.  94). 


APPENDIX   TO   CHAPTER   VI 

KEY  TO  THE  SEVEN  SUBORDERS  OF  THE  ARANEINA 

«i.    With  4  slits  into  lung  sac  [Tetrapneumones].    Che- 
lifer  claw  directed  downward  ;  8  closely  grouped 
eyes      ....        .       ..         .         .  Territelarne 

(Tunnel-weavers) 

«-2.    2  slits  into  lung  sac  [Dipneum ones].    Chelifer  claw 
directed  inward. 

,  mite.  2  rig.  93. 


96 


ZOOLOGY 


Eyes  in  2  transverse  rows ;  most  species  spin 

webs  [Sedentariae]. 
Ci.   Legs  not  spread  flat  out. 

di.  Spinnerets  short  and  inclined  together, 
and  on  under  side  of  abdomen,  which 
is  usually  round. 

e\.    Anterior  row  of  eyes  near  margin 
of  head       .        .        .        . 

62.    Anterior  row  of  eyes  remote  from 
margin  of  head  .... 


Orbitelarm 

(Orb-weavers) 


Betitelarios 

(Line-weavers) 

d\.    Spinnerets  at  end  of  abdomen,  which 

is  elongated Tubitelarias 

(Tube-weavers) 

cj .    Legs  spread  flat  out    .....      Laterigradce 

(Crab  spiders) 
Eyes  in  3  transverse  rows  ;  spin  no  webs,  but 

hunt  prey  [Vagabundse]. 
GI.    Anterior  eyes  smallest  .....  Citigradce 

(Running  spiders) 

c2.   The  anterior  eyes  largest     .        .        .  Saltigradas 

(Jumping  spiders) 


CHAPTER   VII 

THE   CRAYFISH  AND   ITS   ALLIES 

THE  crayfish  belongs  to  the  class  of  Crustacea,  since  it 
breathes  by  means  of  gills,  possesses  two  pairs  of  antennae, 
a  pair  of  mandibles  bearing  palps,  and  a  pair  of  append- 
ages on  all  body  segments  excepting  the  last.  The 
Crustacea  are  divided  into  two  subclasses,  —  Entomostraca, 
of  which  Daphnia  is  an  example,  and  Malacostraca,  to 
which  the  crayfish  belongs.  All  the  Malacostraca  1  have 
19  pairs  of  appendages.2 

The  crayfish,3  which  is  closely  related  to  the  marine 
lobster,4  is  an  inhabitant  of  fresh-water  lakes,  rivers,  and 
pools.  It  thrives  in  diverse  surroundings;  for  some  species 
prefer  cool  mountain  streams  and  others  muddy  pools, 
while  certain  species,  both  in  Europe  and  America,  are 
found  in  brackish  as  well  as  fresh  water.  Indeed,  the 
European  Astacus  fluviatilus  is  said  to  be  frequently 


s,  soft  ;  &<TTpaKov,  shell  (since  the  shell  is  less  hard  than  that 
of  mollusks). 

2  Keys  to  the  six  chief  orders  of  Malacostraca  and  to  families  of  the 
stalk-eyed  Crustacea  will  be  found  in  the  Appendix  to  this  Chapter,  p.  122. 

3  The  old  English  spelling  of  this  word  was  "crevis"  or  "crevice." 
The    ere    came    to    be    spelled    phonetically    cray,   while    vis    became 
changed   to  fish  in   accordance  with  the  popular  nomenclature   of  all 
aquatic  animals. 

4  The  English  word  "  lobster  "  is  from  the  old  English  lopystre,  which  is 
probably  corrupted  from  the  Latin  hcusta,  by  which  term  Pliny  refers  to 
the  lobster. 

H  97 


98  ZOOLOGY 

caught  off  the  Livonian  coast,  even  some  distance  out  at 
sea.  Individuals  of  an  American  species  have  been  taken 
from  a  mineral  spring  impregnated  with  sulphur  and 
magnesia  at  a  temperature  of  70°  Fahr.  (21°  Cent.), 
while  several  kinds  of  the  American  "burrowing"  or 
"  chimney  "-forming  species  have  been  found  in  meadows 
and  clay  bottoms,  often  at  great  distances  from  streams. 
Certain  species  that  are  blind  inhabit  caves  only.  In 
England,  according  to  Huxley,  "  in  granite  districts,  and 
others  in  which  the  soil  yields  little  or  no  calcareous 
matters  to  the  water  which  flows  over  it,  crayfishes  do  not 
occur.  They  are  intolerant  of  great  heat  or  of  much  sun- 
shine ;  hence  they  are  most  abundant  in  those  parts  of 
rivers  which  flow  east  and  west,  and  thus  yield  the  most 
shade  from  the  midday  sun." 

The  food  of  the  crayfish  is  very  varied ;  it  may  be  living 
or  dead,  animal  or  plant.  On  account  of  the  need  of 
calcareous  matters  in  the  food,  crayfishes  are  especially 
fond  of  the  stoneworts  (Chara)  and  various  succulent 
roots,  like  the  carrot.  It  is  said  that  crayfishes  sometimes 
make  excursions  inland  in  search  of  plant  food.  They 
likewise  devour  shells  of  snails,  their  own  cast-off  skins, 
and  occasionally  each  other,  shell  and  all. 

There  are  two  great  groups  or  subfamilies  of  cray- 
fishes. One,  restricted  to  the  Northern  Hemisphere,  is 
found  in  Europe,  Asia,  and  North  America.  The  other  is 
found  in  the  Southern  Hemisphere,  in  Australia,  Tasmania, 
New  Zealand,  Fiji  Islands,  Madagascar,  and  South  America. 
No  crayfishes  have  been  found  on  the  continent  of  Africa, 
or  in  the  rivers  of  northern  Asia  that  flow  into  the 
Arctic  Ocean,  or  in  those  of  southern  Asia.  These  Asiatic 
rivers  are  populated  by  fluviatile  crabs,  to  which  the  cray- 


THE  CRAYFISH  AND  ITS  ALLIES  99 

fishes  of  the  region  have  probably  succumbed.  All  the 
islands  now  inhabited  by  crayfishes,  such  as  England. 
Japan,  and  Cuba,1  were  probably  once  connected  with  the 
mainland. 

The  northern  subfamily  of  crayfishes  contains,  accord- 
ing to  Faxon,  two  genera  —  Astacus  and  Cambarus  —  of 
which  the  latter  can  be  subdivided  into  the  subgenera 
Cambarus  and  Cambaroides.  These  groups  occupy  dis- 
tinct geographical  areas.  The  genus  Astacus  is  found,  in 
the  Old  World,  in  Europe  and  western  Asia  as  far  south 
as  the  Aral  and  Caspian  seas,  and  in  America  in  the  region 
west  of  the  Rocky  Mountains,  draining  into  the  Great  Salt 
Lake  and  the  Pacific  Ocean.  It  is  thus  seen  to  occupy  the 
western  sides  of  the  two  northern  continents.  Likewise 
Cambarus  and  Cambaroides  occupy  the  two  eastern  coasts 
of  the  northern  continents;  for  Cambarus  is  found  in  North 
America  east  of  the  Rocky  Mountains  in  the  region 
bounded  on  the  north  by  Lake  Winnipeg  and  New  Bruns- 
wick and  on  the  south  by  Guatemala  and  Cuba,  while 
Cambaroides  is  limited  to  the  Amoor  River  basin  in  Asia, 
and  to  Japan. 

We  thus  find  among  the  crayfishes  what  is  known  as 
discontinuous  genera;  that  is,  genera  which  now  occupy 
widely  separated  areas,  such  as  Astacus  in  Europe  and 
Pacific  North  America,  but  which  once  ranged  over  the 
intervening  regions  as  well.  From  some  cause,  the 
struggle  for  existence  became  too  severe  in  the  intervening 
regions,  so  that  Astacus  and  Cambarus  were  annihilated  on 
the  eastern  and  western  sides  of  the  continents  respectively. 
In  southern  Asia  we  find  that  the  struggle  was  doubtless 
with  the  successful  river-crab.  It  is  interesting  to  note 

1  It  is  doubtful  whether  Cuba  has  been  connected  with  the  mainland. 


100  ZOOLOGY 

that,  probably  on  account  of  the  preserving  influence  of 
climate,  the  other  animals  and  the  plants  of  the  eastern 
sides  of  the  two  continents  and  those  of  the  western  sides 
are  more  alike  than  those  from  opposite  sides  of  the  same 
continent.  One  of  the  best  pieces  of  evidence  for  the  con- 
clusion of  a  former  hemispherical  distribution  of  the  two 
genera  of  crayfishes  is  that  there  occur  in  the  caves  of 
Carniola  in  southern  Austria  crayfishes  l  belonging  to  the 
genus  Cambarus  —  the  only  known  living  representatives 
of  this  type  in  Europe.  The  mere  fact  that  it  lives  in  a 
cave  is  not  sufficient  to  make  the  Carniola  crayfish  a  Cam- 
.barus,  for  in  North  America  the  genus  has  certainly  not 
originated  under  the  influence  of  subterranean  life ;  it  is 
more  likely  that  the  caves  of  Carniola  have  protected  these 
crayfish  from  the  widespread  destruction  which  has  over- 
whelmed their  fellows  outside. 

Only  one  crayfish,  Cambarus  Bartonii,  is  found  in  New  England, 
and  here,  with  two  or  three  local  exceptions,  only  in  the  rivers  of 
Maine.  This  C.  Bartonii  has  the  widest  geographical  distribution  of 
all  the  northern  species.  C.  Blandingii  is  the  most  widely  distributed 
of  the  southern  species.  C.  pellucides  is  the  blind  species  found  in 
Mammoth  and  Wyandotte  caves. 

The  lobster  (Homarus)  is,  as  we  have  already  seen,  the 
nearest  living  salt-water  relative  of  the  crayfish.  There 
are  only  two  species  of  the  genus  Homarus.  One,  Homarus 
americanus,  occurs  on  our  Atlantic  coast,  the  other, 
H.  vulgaris,  is  the  lobster  of  Europe.  On  our  Pacific 
coast  there  is  the  "spiny  lobster,"  but  this  is  not  closely 
related  to  the  eastern  lobster  (Fig.  95).  The  national  gov- 

1  These  crayfishes  are  blind,  like  the  cave-inhabiting  Cambarus  of 
America. 


THE  CRAYFISH  AND  ITS  ALLIES  101 

ernment  has  transplanted  the  Atlantic  lobster  to  several 
localities  on  the  Pacific  coast,  but  it  is  not  yet  known 
whether  it  will  thrive  there.  The  American  lobster  ranges 
from  Labrador  to  Delaware  Bay,  and  from  near  shore  to  a 


FIG.  95.  —  Palinurus,  the  spiny  lobster.    One-fourth  nat.  size.    From  Rathbun  ; 
drawn  by  H.  L.  Todd. 

depth  of  100  fathoms.  It  attains  its  greatest  size  on  the 
rocky  shores  in  the  cooler  waters  from  Maine  to  Labrador. 
It  migrates  but  little  along  the  coast ;  in  the  fall,  however, 
it  moves  out  into  deep  water,  and  in  the  spring  back  again 


102  ZOOLOGY" 

into  the  shallower  bays ;  the  time  of  migration  depending 
upon  the  length  of  the  season.  It  is  said  to  be  a  nocturnal 
animal,  searching  most  actively  for  its  food  at  night.  The 
sense  which  probably  aids  it  most  in  this  search  is  that  of 
smell,  as  the  attraction  of  the  bait  in  the  traps  —  the  so- 
called  lobster-pots  —  testifies.  In  respect  to  food  it  is,  like 
the  crayfish,  omnivorous. 

Protection  of  the  Lobster.  —  There  has  been  much  differ- 
ence of  opinion  in  regard  to  the  size  at  which  a  lobster 
becomes  mature  and  before  which,  therefore,  it  cannot  be 
caught  without  danger  of  extermination.  The  legislation 
on  the  matter  has  accordingly  been  very  varied.  In  Con- 
necticut the  law  makes  the  limit  six  inches,  while  in 
Massachusetts  and  New  York  it  is  placed  at  ten  and  one- 
half  inches.  Herrick  has  carefully  investigated  the  relation 
of  length  to  maturity,  and  concludes  that,  on  the  Massa- 
chusetts coast  at  least,  the  lobster  becomes  mature  between 
the  limits  of  eight  and  twelve  inches,  and  hence  that  all 
present  legislative  protection  is  insufficient.  The  increasing 
rarity  of  large  lobsters  in  our  markets  testifies  to  the 
correctness  of  this  conclusion. 

Enemies  of  the  Lobster. —  Besides  its  worst  enemy,  man, 
both  the  adult  (particularly  the  egg-bearing  female,  called 
by  fishermen  the  "berry  lobster,"  or  "berry  hen")  and 
young  lobsters  are  attacked  by  many  kinds  of  fish.  Two 
or  three  internal  parasites  are  known  to  infest  the  lobster, 
while  sometimes  it  is  greatly  hampered  in  its  movements 
by  the  number  of  messmates  it  carries  about  attached  to  its 
shell.  Barnacles,  mussels,  tube-forming  worms,  and  various 
seaweeds  are  all  found  at  times  attached  to  the  shell  of  the 
lobster.  Upon  moulting,  however,  the  animal  is  enabled  to 
rid  itself  of  all  these  hangers-on ;  but  this  very  process  of 


THE  CRAYFISH   AND  ITS  ALLIES  103 

moulting,  or  casting  off  the  entire  shell  at  intervals,  is 
attended  with  great  dangers  to  the  lobster,  since  the  animal 
is  so  soft  bodied  as  to  J)e  able  to  offer  little  resistance  to 
its  enemies. 

The  moulting  process  in  the  lobster,  crayfish,  and  other 
Crustacea  is  made  necessary  from  the  fact  that  these  animals 
are  enclosed  in  a  chitinous  covering  which  is  impregnated 
with  salts  of  lime.  It  is  evident  that  an  animal  cannot 
increase  in  size  while  so  encased ;  hence  special  provision 
for  growth  has  to  be  made  by  the  moulting  or  casting  off 
of  the  hard  shell.  This  process  is  accomplished  in  the 
following  manner:  previous  to  the  throwing  off  of  the  old 
skin  a  new  soft  one  is  formed  inside,  the  lime  is  absorbed 
from  the  old  shell  in  a  dorsal  line  along  the  carapace, 
reaching  from  the  rostrum  to  its  posterior  margin.  Ab- 
sorption also  takes  place  at  the  joints  of  the  limbs.  When 
the  lobster  has  attained  this  stage  it  is  dark  in  color,  and 
known  by  fishermen  as  the  "  black  lobster."  The  carapace 
now  splits  along  this  dorsal  median  line  of  absorption,  the 
blood  leaves  the  limbs,  which  are  thus  made  flabbier,  and 
by  involuntary  muscular  movements  they  are  drawn,  large 
claw  and  all,  through  the  joints  of  the  old  shell.  The 
anterior  portion  of  the  body  is  first  drawn  out  through  the 
dorsal  rent,  and  lastly  the  tail.  Not  only  is  the  entire  outer 
covering  cast  off,  but  the  lining  of  the  oesophagus,  stomach, 
and  intestine  as  well,  since  these  organs  are  formed  by  an 
infolding  of  the  skin.  By  means  of  the  return  of  the  blood 
to  the  limbs  and  rapid  absorption  of  water,  the  body  of  the 
lobster  soon  swells  to  a  size  far  beyond  that  of  the  old  shell. 
There  remains  in  the  stomach,  after  moulting,  a  calcareous 
nodule  which  has  long  been  known  by  the  name  of  "crab's- 
eyes."  These  "  crab's-eyes  "  were  formerly  much  sought 


104  ZOOLOGY 

after  and  prized  on  account  of  their  supposed  medicinal 
qualities.  The  function  of  these  gastroliths  or  "  crab's- 
eyes "  was  for  a  long  time  rather  obscure.  It  is  now 
believed  that  during  the  time  of  absorption  of  lime  from 
the  shell,  previous  to  moulting,  the  blood  becomes  strongly 
impregnated  with  lime.  If  all  the  lime  that  must  be  re- 
moved were  to  remain  in  the  blood,  it  would  probably  be 
fatal  to  the  animal ;  hence  it  is  taken  up  by  secreting  cells 
located  in  the  wall  of  the  stomach,  and  there  deposited. 
After  the  old  skin  is  cast,  the  gastrolith  is  soon  absorbed, 


FIG.  96.  — Palsemonetes  vulgaris,  a  common  shrimp.     Nat.  siza. 
Photo,  by  W.  H.  C.  P. 

probably  to  aid  in  strengthening  the  new  shell.  Bits  of 
water-worn  shells,  entire  gastropod  shells,  parts  of  lobster 
coverings,  spines  of  sea-urchins,  etc.,  have  been  found  in 
the  stomachs  of  lobsters  and  crayfish,  which  likewise  would 
probably  have  been  dissolved  and  used  in  hardening  the 
shell. 

Shrimps  and  prawns 1  belong  to  a  thin-skinned,  long-tailed 
family  of  Crustacea.2  They  are  extremely  common  in  bays 

1  These  are  common  names  of  small  Crustacea  applied  chiefly  to  the 
decapod  family  Carididse,*  although  also  applied  to  certain  Schizopods. 
The  term  shrimp  is  applied  to  the  smaller  species,  and  prawns  to  the 
larger.  2  Fig>  QQ. 

*  Kapts,  a  small  marine  crustacean. 


THE  CRAYFISH  AND  ITS  ALLIES  105 

along  our  coast,  and  even  penetrate  into  rivers.  Two  river 
shrimps  1  are  found  in  the  United  States  east  of  the  Missis- 
sippi River.  These  Crustacea  are  able  to  maintain  their 
enormous  numbers  only  by  virtue  of  their  great  repro- 
ductive capacity,  necessitated  by  the  circumstance  that 
they  furnish  almost  the  entire  food  supply  for  many  kinds 
of  fishes  and  other  foes.  Even  in  the  principal  shrimping 
grounds  of  the  United  States  —  such  as  San  Francisco  and 


FIG.  97.  —  Gebia  affinis,  right  side.    Two-thirds  natural  size. 
'  Photo,  by  W.  H.  C.  P. 

New  Orleans  —  there  is  said  to  be  no  diminution  in  the 
numbers  of  shrimps. 

The  Thalassinidae 2  include  certain  crayfish-like  species 
which  live  on  our  coast,  burrowing  in  mud-flats,  where 
they  live  concealed  during  the  day.  On  account  of  their 
being  of  only  medium  size  and  difficult  to  obtain,  they  are 
commonly  little  known.  Our  Eastern  species  are  Gebia 
affinis  (Fig.  97)  and  Oallianassa  stimpsoni. 

The  hermit  crabs  (Paguriclce3)  occupy  a  position  inter- 
mediate between  the  long  arid  short  tailed  Decapods  in 

1  Palcemon  Ohionis  and  Paleomonetes  exilipes. 

2  0a\da-a-Lvos,  color  of  the  sea.  3  -rrdyovpos,  a  kind  of  crab. 


106  ZOOLOGY 

respect  to  the  length  of  their  abdomen.  The  abdomen  is 
soft,  and  the  animal  protects  it  by  inserting  it  within  the 
coiled  shell  of  some  gastropod.  Moreover,  the  abdomen  is 
asymmetrical,  being  coiled  to  one  side  to  correspond  with 
the  shape  of  the  borrowed  house  (Fig.  99).  The  abdominal 
feet  become  degenerate,  with  the  exception  of  the  posterior 
pair,  which  are  modified  into  a  hook-like  process,  by  means 
of  which  the  crab  maintains  itself  securely  in  the  shell. 


FIG.  98.  —  Eupagurus  longi carpus.    Two  individuals  in  shells.    Photo,  while 
alive  by  W.  H.  C.  P. 


When  one  shell  becomes  too  small,  it  is  abandoned  for  a 
larger  one.  Numerous  species  of  hermit-crabs  occur  on 
our  coast,  ranging  from  the  shore  line  to  a  depth  of  several 
hundred  fathoms.  Eupayurus  longicarpus  is  the  little 
active  hermit  found  in  almost  any  tide-pool  from  Massa- 
chusetts Bay  to  the  Gulf  of  Mexico.  Hydroids,  polyps, 
sponges,  often  attach  themselves  to  these  borrowed  shells 
(Fig.  98)  ;  indeed,  a  Chinese  hermit-crab  always  bears  an 
anemone  on  its  large  claw,  with  which  it  plugs  up  the 
aperture  when  obliged  to  retreat  within  its  shell.  One  of 


TIIK   CKAVFISII   AND   ITS  ALLIES  107 

the  East  Indian  hermit-crabs,  the  so-called  palm-crab,  feeds 
upon  cocoanuts,  which  it  opens  by  inserting  its  claws  into 
the  eyes  and  then  breaking  the  shell  upon  the  rocks. 

The  Hippidae  include  certain  oval  animals,  which  bur- 
row, like  a  mole,  head  first,  in  sandy  beaches.  The  name 
of  our  common  eastern  species,  Hippa l  talpoides?  indicates 
this  resemblance  (Fig.  100). 


FIG.    99.  —  Eupayurus    longlcarpus    removed       FIG.  100.  —  Hippa  talpoides. 
from  shell,     x  Ifc.     Photo,  by  W.  H.  C.P.  Nat.     size.      Photo,    by 

W.  H.  C.  P. 

The  Brachyura  are  represented  on  our  shores  by  three 
principal  families,  which  may  be  designated  as  triangular 
crabs,  arched  crabs,  and  square  crabs. 

The  spider-crabs,  or  sea-spiders,  as  they  are  sometimes 
called,  belong  to  the  triangular  crabs.  As  their  name 
implies,  their  legs  are  very  long  and  slender.3  These  crabs 
frequent  oyster-beds  and  sea-bottoms  in  general.  When 

1  From  frrTTos,  horse  ;  used  by  Aristotle  as  the  name  of  a  kind  of  crab. 

2  Like  talpa,  the  mole.  3  Fig.  101. 


108 


ZOOLOGY 


seen  stalking  over  such  uneven  surfaces,  the  advantage  of 
these  stilt-like  legs  is  at  once  evident.  The  surface  of  the 
body  of  some  species  of  spider-crabs  is  hairy,  entangling 
inorganic  matter,  while  hydroids,  barnacles,  and  algse  attach 
themselves  to  the  shell.  Libinia  emarginata  and  dubia, 
the  former  ranging  from  Maine  south,  and  the  latter  from 
Cape  Cod  to  the  Gulf  of  Mexico,  are  our  two  species  which 


FIG.  101.  —  Libinia  dubia.    One-third  nat.  size.     Photo,  by  W.  H.  C.  P. 

undergo  such  concealment.  The  great  Japanese  spider- 
crab  is  said  to  be  the  largest  of  all  the  Crustacea,  some 
individuals  measuring,  from  tip  to  tip  of  the  first  pair  of 
legs,  18  to  20  feet. 

The  edible  crab  is  a  typical  arched  crab.  It  is  so  called 
because  the  carapace  is  arched  in  front.  The  carapace  is 
also  broader  than  long,  and  narrower  behind  than  in  front. 


THE  CRAYFISH  AND  ITS  ALLIES 


109 


The  legs  of  this  family  are  short  and  broad,  and  in  some 
species  the  posterior  pair  is  especially  broad  —  an  adapta- 
tion for  swimming.  These  crabs 
may  be  divided  into  two  groups 
—  the  burrowing  crabs  and  swim- 
ming crabs.  To  the  burrowing 
crabs  belongs  the  genus  Cancer 
(Fig.  102),  which  includes  the 
edible  crab  of  Europe,  especially 
prized  in  England,  together  with 
several  American  species;  while 
our  common  edible,  soft-shelled 
or  blue  crab,  Callineetes  hastatus 
(Fig.  103),  and  the  beautiful  "lady  crab"  (Fig.  104) 
belong  to  the  swimming  group.  Representatives  of  other 
families  of  crabs  are,  however,  eaten  in  various  localities 
and  by  various  peoples.  For  example,  our  little  Pinnotheres 


Fia.  102.  —  Panopeus  sac/i, 
allied  to  Cancer.  The  mud- 
crab.  One-half  nat.  size. 
Photo,  by  W.H.C.P. 


FIG. 103. 


Callineetes  Jiastatus,  blue  crab.    Reduced  to  one-third.    Photo, 
by  W.  H.  C.  P. 


110 


ZOOLOGY 


ostreum  (Fig.  105),  found   in    the  mantle  chamber  of  the 
oyster,  is  eaten  by  us  together  with  the  oyster  or  separately. 


FIG.  104.  —  Platyonichus  oceltatus,  lady  crab.    Reduced  to  one-third. 
Photo,  by  W.  H.  C.  P. 


The  fiddler  crabs  are  representative  of  the  square  crabs. 
These  are  the  familiar  animals  which  crowd  salt  marshes 
and  run  sideways  to  and  from  their  burrows.  One  claw  is 

much  larger  than  the  other. 
When  the  crab  is  disturbed, 
the  large  claw  is  brandished 
in  a  manner  which  has  been 
likened  to  the  movements  of 
a  fiddle  as  one  plays  upon 
it.  Grelasimus  pugnax  is  the 
most  abundant  species,  and 
ranges  from  Cape  Cod  to  the  Gulf  of  Mexico.  Together 
with  Cambarus  it  does  much  damage  by  burrowing  in  the 
levees  of  the  Mississippi  River  (Fig.  106). 


FIG.  105.  —  Pinnotheres  ostreum.    X  4. 
From  Rathbun. 


THE  CRAYFISH  AND   TTS  ALLIES 


111 


The  economic  im- 
portance of  the  Deca- 
poda  may  be  inferred 
from  the  fact  that 
the  receipts  for  the 
lobster  alone,  taken 
and  sold  by  United 
States  fishermen,  is 
estimated  for  1892 


FIG.    100.  —  Gelasimiift   puynax.      Nat.   size. 
Fronto-dorsal  view.   Photo,  by  W.  H.  C.  P. 

at  one  million  dollars.  The  yield 
to  Canadian  fishermen  was  in  ad- 
dition worth  half  a  million  dollars. 
From  the  United  States  Fish  Com- 
mission Bulletin  for  1890-91  we 
find  that  the  blue-crab  fisheries  on 
the  Atlantic  and  Gulf  coasts  re- 
turned almost  half  a  million  dol- 
lars, while  the  shrimp  catch  in  the 
same  waters  brought  nearly  a 
quarter  of  a  million  dollars  more. 
The  latter  industry  on  the  Cali- 
fornia coast  is  much  greater,  for 
the  shrimp  trade  of  San  Francisco 
Bay  alone  is  valued  at  a  quarter  of 
a  million  dollars  yearly. 

The  remaining  orders  of  Mala- 
costraca  maybe  briefly  mentioned. 
The  Stomatopoda*  include  only  FlQ.  107.  _  s?uMff  enJ)9MS(J)  the 

Squilla,2    the    mantis    shrimp,    SO       mantis  shrimp.  Dorsal  aspect. 

From  Bigelow. 

1  (rr6/ia,  mouth  ;  TTO^S,  foot. 

2  cric/XXa,  classic  name  for  a  marine  crustacean. 


112 


ZOOLOGY 


called  because  of  a  certain  resemblance  to  the  mantis 
insect  (Fig.  107).  This  animal  is  found  on  our  east 
coast,  where  it  burrows  in  the  sand.  It  is  a  little  longer 
than  a  crayfish.  Being  hard  to  catch,  it  is  not  much 
used  as  food.  The  Cumacea  include  a  few  small  marine 
Crustacea,  not  ordinarily  seen.  They  are  of  interest  be- 
cause of  the  reduced  carapace  which  is  transitional  to  the 
condition  found  in 
the  lower  Crustacea. 
The  Isopoda 1  include 


FIG.  108.  —  Oniscus,  the 
sow-bug.  Dorsal  view. 
Nat.  size.  Photo,  by 
W.  H.  C.  P. 


FIG.  109.  —  Talorchestia  fangicorni*,  the 
beach  flea.  Nat.  size.  Photo,  by  W.  H. 
C.  P. 


the  sow-bugs  or  wTood-lice  (Fig.  108),  noteworthy  for 
forming  the  largest  group  of  land  Crustacea,  and  certain 
marine  and  fresh-water  groups.  The  Amphipoda2  are 
exclusively  aquatic  creatures,  found  under  decaying 
vegetation  on  beaches  of  lakes  or  the  sea  (Fig.  109),  and 
crawling  amidst  marine  hydroids.  Being  laterally  com- 
pressed, the  Amphipods  tend  to  lie  on  one  side  when  at 
rest. 


1  ftros,  equal ;  Trotfs,  foot. 


,  both  ;  TTOI/S,  foot. 


THE  CRAYFISH  AND  ITS  ALLIES  113 

Edible  Lobsters* — The  American  lobster,  Homarus  Ameri- 
canus,  differs  little  in  appearance  from  the  European  lob- 
ster, H.  vulgaris.  Formerly  the  American  lobster  attained 
the  greater  size,  but  the  excessive  catches  of  our  species  in 
the  last  few  years  are  rapidly  doing  away  with  this  differ- 
ence. The  so-called  Norwegian  lobster  finds  its  way  into 
European  markets,  while  on  our  Californian  coast  the  so- 
called  spiny  lobster  or  sea-crayfish  takes  the  place  of  our 
true  Atlantic  lobster,  and,  like  the  latter,  is  said  to  be  in 
danger  of  extermination  on  account  of  overfishing. 

Edible  Crayfish.  —  The  nearest  fresh- water  ally  to  the 
lobster  —  the  crayfish  —  has  not  yet  attained  the  pop- 
ularity in  our  markets  which  it  possesses  in  Europe, 
particularly  in  France.  So  much  is  the  crayfish  esteemed 
in  Paris  that  the  enormous  crayfish  farms  throughout 
France  are  unable  to  supply  that  city,  consequently  cray- 
fishes are  imported  in  considerable  quantities  from  Ger- 
many. In  America,  it  is  our  French  population  mainly 
that  makes  a  market  for  the  crayfish.  Astacus  nigres- 
cens  is  the  crayfish  sold  in  San  Francisco  markets.  On 
the  Atlantic  coast,  New  York  and  New  Orleans  are  the 
main  centres  of  consumption.  Cambarus  affinis,  taken 
from  the  Potomac  River,  is  the  crayfish  found  in  the  spring 
in  the  New  York  markets.  Later  in  the  season  this 
market  is  supplied  by  Q.  virilis  and  immunis,  which  are 
shipped  from  Montreal,  Milwaukee,  and  other  Western 
cities. 

Edible  Crabs.  —  Of  the  crabs  which  reach  our  market 
the  most  important  is  the  blue  crab.  These  crabs  are 
kept  moored  in  floating  boxes  until  they  have  moulted, 
and  then  they  are  sent  to  market  as  soft-shelled  crabs. 


114  ZOOLOGY 

The   shore  crabs,  Cancer,  are  little  eaten  in   the   United 
States.1 

Edible  Carididae.  — The  shrimps  and  prawns  have  within 
recent  years  begun  to  appear  in  large  numbers  in  the 
Eastern  markets.  For  many  years  the  Pacific  species 


FIG.  110.  —  Limulus  polyphemus,  the  king-crab  or  horseshoe-crab. 

have  been  dried    and    shipped   by  the  Chinese   in   large 
quantities  to  China. 

1  Very  unfortunate  is  the  destruction  of  the  "king-crab,"  Limuhis, 
which  is  only  distantly  related  to  the  Decapoda.  In  Delaware  Bay  they 
are  caught  in  great  numbers  and  ground  up  as  fertilizer.  As  they  are 
taken  only  during  the  breeding  season,  they  are  being  rapidly  extermi- 
nated. The  American  Limulus  belongs  to  an  order  entirely  unrepresented 
on  the  European  coast  (Fig.  110). 


THE  CRAYFISH  AND  ITS  ALLIES 


115 


Development  of  Lobsters.  —  Lobsters  lay  eggs  in  July  and 
August.  In  the  fall  they  migrate  to  deep  water,  and  pass 
the  winter  there.  In  the  spring  they  migrate  back  to  the 
shore  —  the  females  tarrying  behind  the  males  until  the 
eggs  of  last  summer,  which  she  still  carries  attached  to 
her  swimmerets,  shall  be  further  advanced.  In  June  the 
young  hatch  out,  moult,  and  swim  to  the  surface.  The 


FIG.  111.  —  An  early  stage  of  develop- 
ment of  egg.  Appendages  becom- 
ing bifid.  Paired  dotted  areas 
above  indicate  eyes ;  these  are  fol- 
lowed by  the  first  three  paired  ap- 
pendages :  antennules,  antennae, 
and  mandibles.  Below  in  the  mid- 
dle line  is  the  forming  tail ;  above 
is  the  mouth.  After  Herrick. 


FIG.  112.  —  Surface  view  of  egg 
nauphius.  Antennas  show  begin- 
ning of  segmentation;  mandibles 
and  maxillae  seen  on  each  side  of 
the  abdomen.  Embryo  16-18  days 
old.  X  25.  From  Herrick. 


female  now  moults,  but  does  not  spawn  again  for  a  whole 
year  ;  that  is,  she  spawns  in  alternate  years.  The  number 
of  eggs  carried  varies  with  the  age  of  the  female ;  middle- 
aged  lobsters  may  carry  up  to  one  hundred  thousand  eggs, 
but  the  old  or  young  ones  as  few  as  three  thousand.  The 
egg  as  freshly  laid  is  about  1.5  millimetres  in  diameter  and 
is  stored  with  food  material,  called  yolk,  much  as  in  the 
case  of  the  hen's  egg.  As  in  the  chick,  the  development 


116 


ZOOLOGY 


takes  place,  as  it  were,  on  top  of  the  egg  (Figs.  Ill,  112). 
Eyes  and  mouth  appendages  early  make  their  appearance; 
then  the  other  appendages,  and  the  tail  (Fig.  113).  For 
a  long  time  the  back  of  the  thorax  is  greatly  distended  by 
the  yolk  stored  there,  and  the  eyes  are  huge  (Fig.  114). 

Immediately  after  hatching,  the  young  lobster  is  about 
one-third  of  an  inch  long.  The  eyes  are  still  abnormally 
large,  the  telson  is  spatulate,  and  the  abdomen  is  without 


FIG.  113.  —  Surface  view  of  embryo  FIG.  114.  —  Lobster  embryo.  Cl  days 
with  all  of  thoracic  appendages  old  ;  eyes  have  developed  pigment, 
formed.  The  forked  telson  partly  X  15.  From  Herrick. 

overlies  the  brain.  Note  the  large 
eyes,  which  are  yet  without  pig- 
ment. Embryo  about  21  days  old. 
X  25.  From  Herrick. 

swimmerets.  On  account  of  its  resemblance  to  the  Schizop- 
oda,  the  larva  at  this  stage  is  known  as  the  "  Schizopod 
larva"  (Fig.  115).  In  moulting  for  the  fourth  time,  the 
exopods  are  lost  from  the  future  walking  appendages,  and 
the  animal  resembles  a  lobster  except  for  its  small  size  (Fig. 
115#).  During  these  early  moultings  the  young  lobsters 
undergo  a  terrible  mortality,  so  that  out  of  ten  thousand 
embryos  hardly  two,  on  the  average,  survive.  After  the 


THE  CE  AY  FISH  AND  ITS  ALLIES 


117 


fifth  or  sixth  moult  the  little  lobsters  sink  to  the  bottom, 
and  then  begin  their  journey  shoreward.  From  this  time 
until  they  are  about  four  inches  long,  only  very  few  indi- 
viduals have  ever  been  seen.  This  is  due,  it  is  said,  to 
the  fact  that  they  hide  deep  down  among  the  rocks,  where 
they  cannot  be  dredged.  When  they  are  four  inches  long 
or  so,  they  become  bolder,  leave  the  rocks,  and,  like  the 


FIG.  115.  —  Larval  view  of  lobster,  extracted  from  an 
egg  which  was  about  ready  to  hatch.  The  concretions 
in  the  intestine  are  destined  to  go  into  the  newcuticula 
after  moulting.  X  25.  From  Herrick. 


adults,  make  burrows  for  themselves  in  the  sand  or  under 
stones. 

Development  of  Crayfish.  —  The  crayfish  develops  simi- 
larly to  the  lobster,  —  from  a  large  egg  filled  with  yolk. 
The  early  stages  are  much  like  those  of  the  lobster ;  but 
those  changes  which  in  the  lobster  take  place  during  the 
first  three  stages  of  free  life  are  in  the  crayfish  passed  in 
the  egg.  Consequently  at  the  time  the  crayfish  hatches  it 


118 


ZOOLOGY 


is  almost,  but  not  exactly,  like  an  adult  crayfish  except 
in  size.  The  telson  of  the  just-hatched  crayfish  has,  to  be 
precise,  a  somewhat  more  oval  form,  and  the  first  pair  of 
swimmerets  are  undeveloped;  but  these  differences  soon 
disappear. 


FIG.  lloa.— Third  larval  stage, 
lateral  view.  Note  the  dif- 
ference between  this  and 
the  adult.  X  11.  From 
Herrick. 


Regeneration  of  Lost  Parts.  — If  you  attempt  to  pick  up 
a  crab  by  one  of  its  claws,  you  frequently  find  yourself  in 
possession  of  a  portion  of  the  leg  only,  while  the  crustacean 
has  made  good  its  escape.  Moreover,  it  will  be  seen  that 
the  leg  always  separates  at  a  certain  place  ;  namely,  be- 
tween the  second  and  third  segments.  This  is  the  place 
where  a  fusion  occurs  between  two  segments  which  are  free 


THE  CRAYFISH  AND  ITS  ALLIES  119 

in  the  first  larval  stage.  This  power  of  defensive  mutila- 
tion occurs  in  those  appendages  which  are  most  apt  to  be 
seized,  —  namely,  the  five  thoracic  legs,  —  and  is  wholly 
under  the  control  of  the  reflex  nervous  system,  for  it  may 
occur  when  the  entire  voluntary  nervous  system  has  been 
removed.  The  leg  of  a  dead  crustacean  shows  no  such 
capacity.  If  the  leg  of  a  lobster  is  cut  off  at  some  point 
distal  to  that  of  normal  rupture,  the  limb  will  later  be 
found  cast  off  up  to  this  point.  Here  a  sort  of  double 
membrane  or  diaphragm  exists,  with  a  central  opening 
only  large  enough  to  admit  the  passage  of  nerves  and 
blood-vessels.  Upon  rupture  this  passage  is  soon  plugged 
up  by  coagulated  blood  —  clearly  a  device  to  prevent  ex- 
cessive hemorrhages.  Soon  after  a  leg  is  cut  off  a  papilla- 
like  body  grows  out  from  the  stump  of  the  limb,  develops 
into  the  shape  of  a  small  limb,  and  grows  larger,  with 
each  successive  moult,  until  the  normal  size  is  reached. 
The  antennae,  too,  are  much  exposed  to  injury,  but  with 
them  autotomy  is  not  practised.  They  begin  to  grow  out 
at  the  place  of  injury,  and  at  least  one  moult  is  necessary 
for  their  complete  restoration. 

Abnormalities  in  the  claws  of  the  lobster  are  not  un- 
common. The  thumb-like  protuberances  of  the  next  to 
the  last  of  the  joints  of  the  great  claw  is  sometimes  bifid, 
or  carries  a  large  wart.  The  finger  which  opposes  the 
thumb  is  also  sometimes  forked  (Fig.  116).  Many  of 
these  abnormalities  are  probably  due  to  injury  of  the  claw; 
but  others  cannot  be  explained  in  this  way.  For  instance, 
cases  have  been  observed  of  lobsters  having  crushing 
claws  of  equal  size  on  the  two  sides  of  the  body.  An 
antenna  has  been  seen  replacing  an  eye,  and  this  result 
may  be  obtained  by  cutting  off  an  eyestalk  near  its  base 


120 


ZOOLOGY 


when  an  antenna  will  regenerate  (Fig.  117),  one  or  two 
extra  oviducts   may   occur,  or   double  monsters  —  sort  of 

Siamese  twins  —  may  be  hatched 
out.  Similar  monstrosities  are 
found  in  other  arthropods. 

Physiological  Division  of  Labor. 
—  The  difference  between  a 
"  highly  developed  "  animal  and  a 
lowly  organized  one  is  not  first 
of  all  a  difference  of  size  nor  a 
difference  in  the  number  of  parts, 
-  just  as  a  large  population  or 
numerous  cities  are  not  the  pri- 
mary characteristics  of  a  highly 
civilized  state.  But  just  as  a 
complex  civilization  is  one  in 
which  each  of  the  different  citizens 
has  his  own  special  task  to  per- 
form for  the  commonwealth,  so 
a  highly  developed  organism  is 
one  in  which  each  different  organ 
has  its  special  r61e  to  play.  The 
worm  Nereis  has  more  segments 
to  the  body  than  the  crayfish,  but 
these  segments  are  very  nearly 

FIG.  116,-Two  abnormal  claws,    alike  —  the  parapodia  especially 
Upper  figure  shows  a  double    are  quite  similar.    In  the  crayfish, 

to^^rthere^extS    on  the  other  hand>   the  append- 
finger.    From  Herrick.  ages    are   dissimilar.      Each  pair 

has  a  special  function  to  perform 

and  is  specially   adapted,   often   complexly   fashioned,   to 
meet  this  need.     What  is  true  of  the  appendages  is  like- 


THE  CRAYFISH  AND  ITS  ALLIES 


121 


wise  true,  to  an  equal  degree,  of  the  internal  organs.  The 
internal  organs  of  Nereis  are  repeated  in  each  segment;  but 
in  the  crayfish  the  egg-ducts  lie  in  one  segment,  the  heart 
in  another  part  of  the  body,  and  so  on.  Some  of  the  seg- 
ments have  given  up  one  or  more  functions  to  perfect  a 


FIG.  117.  —  Eyestalks  of  a  Decapod  dissected  out.  On  the  right  an  antenna 
has  regenerated  in  place  of  the  amputated  eye.  opt.,  optic  nerve.  After 
Herbst. 

single  one  in  which  it  has  specialized.  There  has  been  a 
division  of  labor  between  the  different  parts  of  the  body, 
and  in  consequence  a  greater  perfection  in  the  performance 
of  each  function.  More  perfect  fulfilment  of  function  is 
the  result  of  physiological  division  of  labor,  just  as  a  higher 
civilization  is  the  result  of  individual  division  of  labor. 


122 


ZOOLOGY 


APPENDIX  TO   CHAPTER  VII 


KEY    TO    THE    SIX    CHIEF    ORDERS    OF    MALACOSTRACA 


Body  segments,  20  ;  abdomen  with  7  segments  ; 

at  least  1  pair  of  maxillipeds. 
61.   Cephalothorax  with  carapace,  at  least  2  pairs 

of  maxillipeds  [Thoracostraca]. 
Ci.    Eyes  stalked. 

d\.  No  uncovered  thoracic  segments  ;  3 
or  2  pairs  of  maxillipeds,  and  5  or 
6  pairs  of  legs  .  .  .  * 


c?2.  3  free  thoracic  segments  ;  5  pairs  of 

maxillipeds  ;  3  pairs  of  legs 
Cg.   Eyes  not  stalked  ;   4  to  5  thoracic  seg- 
ments not  covered  by  carapace  ;  2  pairs 
of  maxillipeds  ;  6  pairs  of  thoracic  legs 
62.    Cephalothorax    without    marked    carapace; 
usually   7   free   thoracic    segments  ;    only 
1  pair  of  maxillipeds  ;    eyes  not  stalked 
[Arthrostraca]. 

d.   Body  usually  broad  ;  abdomen  with  short, 
often-fused  segments,   and  with  gills 
on  legs          ...... 

c2.   Body    laterally    compressed  ;     abdomen 
mostly  elongated,  with  3  pairs  of  swim- 
ming legs,  and  behind  them  3  pairs  of 
springing  legs       .         ... 

a2.  Body  segments,  21,  enclosed  in  bilobed  shell  ; 
abdomen  with  8  segments  ;  the  last  2  without 
appendages  ;  no  maxillipeds  [Leptostraca] 


Podopthalmata 

(Ex.  Crayfish) 

Stomatopoda 


Cumacea 


Isopoda 


Amphipoda 


Nebalice 


The  crayfish  belongs  to  the  order  Podopthalmata.     The  following  is  a 
key  to  the  most  important  families  of  this  order :  — 

a\.  3  pairs  of  maxillipeds  which  differ  in  form  from 
the  following  5  pairs  of  thoracic  legs  ;  the  latter 
are  locomotor,  and  often  end  in  pincers  [sub- 
order Decapoda]. 


APPENDIX  TO   CHAPTER    VII  123 

61.  Body    mostly    depressed ;     antennae    short ; 

abdomen  short  and  folded  under  the  cepha- 
lothorax,  with  1  to  4  pairs  of  appendages, 
and  usually  without  tail-fin  [superfamily 
Brachyura] . 

cj..  Male  duct  opens  on  thoracic  plate  ;  ce- 
phalothorax  usually  quadrangular,  at 
times  transversely  oval;  anterior  lateral 
area  (liver  area)  of  carapace  small ; 
usually  fewer  than  9  pairs  of  gills;  orbits 
look  forward  or  obliquely  downward  .  Catometopa 

(Square  Crabs ;  Fiddler-crabs) 
c2.   Female  opening  on  broad  thoracic  plate  ; 
male  opening  on  coxa  of  5th  pair  of 
thoracic  legs  ;  9  pairs  of  gills. 
di.    Cephalothorax  broad,  diminished  be- 
hind, bowed  in  front ;   liver  area 
large  ;  orbits  directed  obliquely  up- 
ward and  forward .        ..      -.        ..         Cyclometopa 

(Arched  Crabs) 

d-2.   Cephalothorax  triangular,  anteriorly 
pointed,  with  longer  or  shorter  ros- 
trum ;  liver  area  small ;  orbits  di- 
rected outward      .         .        .        .  Oxyrhyncha 
(Triangular  Crabs ;  Spider-crab?) 

62.  Body  mostly  elongated  ;  antennae  long ;  ab- 

domen long,  not  bent  under,  or  only  partly 
so,  typically  with  5  pairs  of  legs  and  a  large 
tail-fin  [superfamily  Macrura]. 
ci.   Last  pair  of  thoracic  legs  shoved  back- 
ward and  rudimentary. 
di.   Last  thoracic  segment  not  free ;  ab- 
domen with  hard  shell,  hinder  half 
turned  under;   first   pair  of  legs 
typically  non-chelate    .        ,        . ;  Hippidce 

(Mole-crabs) 

d2.  Last  thoracic  segment  free  ;  abdomen 
typically  with  thin  cuticula,  un- 
symmetrical  and  with  rudimentary 
legs ;  first  pair  of  legs  very  large, 
chelae  unsymmetrical  .  .  .  Paguridce 

(Hermit-crabs) 


124 


ZOOLOGY 


C2.    Last  pair  of  thoracic   legs   not  shoved 

backward. 

di.   Antennae,  without  squame  ;  first  pair 
of  thoracic  legs  chelate  ;  cephalo- 
thorax  with  2  longitudinal  lines    . 
d%.    Antennae  with  squame. 

e\.  Squame  small ;  antennules  and 
antennae  near  each  other  ;  first 
pair  of  thoracic  legs  very  heavy 
with  great  chelae;  cephalo- 
thorax  with  cross-suture  ;  gills 
brush-like 


Thalassinidce 


Astacidce 
(Ex.  Crayfish) 


€2.  Squame  large  ;  antennae  usually 
under  antennules ;  first  pair 
of  thoracic  legs  with  small 
chelae  ;  cephalothorax  without 
cross-suture,  gills  laminate 

{Shrimps  and  Prawns) 

2  pairs  of  maxillipeds   resembling  the  6   following 
pairs  in  being  bifid  [suborder  SchizopodaJ. 


CHAPTER   VIII 

THE  DAPHNIA  AND   ITS   ALLIES 

Relationships. — Daphnia1  belongs  to  the  division  of 
Crustacea  called  Entomostraca.2  The  Entomostraca  3  are 
distinguished  from  the  higher  Crustacea  —  the  Malacos- 
traca — by  the  negative  character  that  the  number  of 
segments  and  appendages  in  the  body  is  variable,  instead 
of  there  being  constantly  19  pairs  of  appendages. 

The  group  of  Entomostraca  to  which  Daphnia  belongs 
comprises  the  more  primitive  of  living  Crustacea.  They 
occur  in  both  fresh  and  salt  water  and,  excepting  Protozoa, 
are  the  most  abundant  aquatic  animals.  They  are  of  great 
economic  importance,  since  they  constitute  the  main  food 
supply  of  fish.  On  the  coast  of  Norway  and  Scotland  the 
fishermen  prepare  for  a  catch  of  herring  or  mackerel  when 
the  sea  becomes  red  with  Entomostraca.  Whalers  like- 
wise seek  their  booty  where  these  Crustacea  are  abundant 
on  the  open  seas,  for  even  the  whalebone  whales  devour 
the  small  animals  in  great  quantity,  straining  them  out  of 
the  sea-water  by  means  of  their  whalebone  strainers.  De- 
spite all  their  enemies,  the  numbers  of  Entomostraca  are 
maintained  by  virtue  of  an  enormous  fertility.  The 

1  From  Aa0j/r;,  daughter  of  the  river-god  Peneus  ;  she  was  transformed 
into  a  laurel  tree. 

2  evTojjwv,  cut  into,  segmented  ;  6ffrpaKov,  shell. 

8  The  five  orders  of  Entomostraca  may  be  distinguished  by  means  of 
the  key  given  at  the  end  of  this  Chapter,  page  131. 

125 


126  ZOOLOGY 

Entomostraca  are  rich  in  species  also,  partly  because  they 
occur  in  such  diverse  environments.  Thus  they  live  in 
fresh  water,  in  the  sea,  and  even  in  the  Great  Salt  Lake 
and  in  vats  where  salt  is  crystallized  out.  They  live  in 
little  pools,  such  as  dry  up  in  summer.  They  are  found 
also  as  parasites  on  the  gills  or  in  the  skin  of  fishes. 

Habitat  and  Food.  —  Daphnia1  lives  in  ponds,  lakes,  and 
slow-running  streams  over  all  the  globe.  During  the  fall 
in  northern  latitudes  the  Daphnias,  of  at  least  certain 
species,  lay  fertilized  eggs,  called  winter  eggs,  which  may 
lie  dormant,  however,  not  merely  for  the  winter  but 
throughout  an  entire  year.  During  most  of  the  year 
females  alone  occur  and  unfertilized  "summer  eggs"  are 
alone  produced. 

The  abundance  of  Daphnia  in  any  pond  is  determined 
by  a  number  of  causes.  One  of  the  most  important  of 
these  is  food.  The  food  of  Daphnia  consists  chiefly  of 
fresh-water  algae,  such  as  nostocs  and  diatoms ;  and  it  has 
been  shown  that  the  abundance  of  Daphnia  in  a  pond  is 
closely  determined  by  the  abundance  of  the  kind  of  alga 

1  Key  to  the  principal  genera  of  the  family  Daphnidse  :  — 

a\.     Head  rounded,  not  beaked. 

bi.  Antennules  long;  abdomen  not  wholly  cov- 
ered by  shell  .  .  ./:  .'  .  .  Moina 

b-2.     Antennules    short;   whole  body  enclosed  in 

shell     .         .         .,.-./.„        .         .    CeHodaphnia 
«2.     Head  beaked  below. 

61.  Beak  slight ;  shell  angled  below  or  extending 
in  long  spines  from  lower  angle  ;  pigment 
spot  roundish Scapholeberis 

ft2-     Shell  rounded  below,  with  a  blunt  spine  above  ; 

pigment  spot  elongate          ....    Simocephalus 

&3.  Shell  extending  in  sharp  spine  at  upper  pos- 
terior angle ;  pigment  spot  small  .  .  Daphnia 


THE  DAPHNIA   AND  ITS  ALLIES 


127 


which  forms  its  principal  food.  Another  factor  upon 
which  the  number  of  Daphnia  in  a  pond  depends  is  tem- 
perature. A  high  temperature  seems  to  be  unfavorable  to 
Daphnia,  so  that  not  the 
summer,  but  the  spring  and 
autumn  are  its  periods  of 
maximum  reproductive  activ- 
ity. This  activity  is  like- 
wise checked  in  winter  even 
though  there  is  plenty  of 
food. 

The  family  Branchiopoda x 
is  closely  allied  to  the  Clado- 
cera.  The  common  repre- 
sentative of  this  family, 
Branchipus,  has  an  elongated, 
distinctly  segmented  body 
which  carries  eleven  pairs 
of  lobed,  leaf -like  feet,  func- 
tioning both  as  respiratory 
and  locomotor  organs.  Like 
Daphnia,  Branchipus  pro- 
duces winter  eggs  which  can 
withstand  desiccation  even 


FIG.   118.  —  Apwt  glacialis,   ventral 
aspect,     abd.  /.,   abdominal  feet; 
ant.  1,  antennule ;  ant.  2,  antenna ; 
Ibr.,  labrum;  md.,  mandible;  mx., 
for    years;      indeed,    in    SOme        first  maxilla;  ov.,  aperture  of  ovi- 

cases,    a   certain    amount   of      duct ;  s/.^    sub-frontal  plate ; 

sh.  yl.,  shell-gland;  th.f.,  thoracic 
feet;  th.f.  1,  first  thoracic  foot. 
After  Bernard. 


desiccation  is  a  prerequisite 
of    hatching.       Apus    differs 
from  Branchipus  in  having  a  broad  shield  (Fig.  118). 
The  family  Ostracoda2  comprises  some  very  abundant, 


*,  foot. 
,  shell  of  a  testacean  ;  e?5os,  like. 


128 


ZOOLOGY 


minute,  bean-shaped  little  crustaceans,  which  have  to  move 
their,  appendages  very  vigorously  to  support  their  heavy 
bodies  in  the  water.  The  Ostracods  are  found  in  almost 
all  pools  and  streams,  especially  in  the  early  spring.  Many 
of  them  seem  to  be  exclusively  parthenogenetic. 


FIG.  119.  —  Acartia,  a  marine  Copepod.     Greatly  magnified.    Photo,  by 
W.  H.  C.  P. 

Of  the  Copepoda l  the  commonest  fresh- water  genus  is 
Cyclops,  which  occurs  in  a  similar  habitat  with  Daphnia 
and  is  sometimes  found  even  in  pure  drinking  water. 
The  female  carries  a  conspicuous  egg-sac  011  each  side  of  the 
abdomen,  and  reproduction  occurs  with  such  rapidity  that 

oar  ;  TTO^S,  foot. 


THE  DAPHNTA   ANT)  ITS  ALLIES 


129 


one  Cyclops  might,  under  the  most  favorable  conditions, 
have  5,000,000,000  descendants  in  one  year.  It  is  conse- 
quently easy  to  understand  how  Cyclops  often  becomes 
the  most  abundant  entomostracaii  in  our  waters,  and  how 
in  some  lakes  it  has  been  found  that  there  are  over  one 
million  of  them  to  each  square  metre  of  water  surface. 
Large  numbers  of  the  Copepoda  are  marine.  One  of  the 
most  common  is  Acartia  (Fig.  119),  which  swarms  to  such 


FIG.  120.  —  Mussel-shell  bearing  barnacles  (Balanus).     Photo,  by  W.  H.  C.  P. 

an  extent  on  the  surface  of  the  water  as  to  make  great 
phosphorescent  areas. 

Barnacles  are  the  only  attached  non-parasitic  Crustacea. 
Certain  species  of  them  are  found  fastened  to  rocks  on  the 
seashore  at  low-tide  mark.  If  you  watch  barnacles  in  rock 
pools,  you  can  see  them  open  the  valves  of  their  shells, 
protrude  their  elongated  appendages,  which  together  form 
a  sort  of  rake,  and  pull  in  particles  which  happen  to  be  float- 
ing about  them.  Other  species  of  barnacles  attach  them- 
selves to  floating  seaweed,  ship  bottoms,  and  whales  ;  under 
these  circumstances,  despite  their  sessile  habit,  they  enjoy  a 
constant  change  of  locality.  Barnacles  doubtless  gain 
great  protection  from  the  circumstance  that  they  are 


130 


ZOOLOGY 


sessile  and  enclosed  in  shells  ;  but  their  peculiar  habits 
have  given  rise  to  certain  peculiarities  in  reproduction. 
They  are  hermaphroditic;  i.e.  both  male  and  female  germ- 
cells  occur  in  the  same  individual.  Despite  this  fact, 
dwarf  male  individuals  are  occasionally  found  inside  the 
shell  of  the  barnacle  ;  these  are  known  as  "  complemental 
males."  The  general  form  of  the  barnacles  has  also  be- 
come greatly  modified  by  their 
sessile  habit,  so  that  they 
were  long  regarded  as  mol- 
lusks,  until  it  was  shown  that 
the  larvae  are  almost  exactly 
like  those  of  other  Ento- 
mostraca. 

Trilobites1  are  extinct  giant 
'  Entomostraca,  closely  allied 
to  Branchipus.  They  were 
immensely  abundant  in  early 
geologic  times,  and  their  re- 
mains form  a  large  part  of 
certain  rocks.  They  had  a 
segmented  body,  with  bifid 
appendages  and  long  antennae, 

FIG.  121.  -  A  restoration  of  the    and  their  compound  eyes  were 

borne  on  the  great  frontal 
shield.  Some  of  them  were 
nearly  half  a  metre  long. 


ventral  aspect  of  a  Trilobite. 
Note  in  particular  the  charac- 
ter of  the  appendages.  After 
Beecher. 


Having  three  lobes. 


APPENDIX  TO   CHAPTER    VIII  131 

APPENDIX  TO   CHAPTEE  VIII 

KEY    TO    THE    FIVE    ORDERS    OF    ENTOMOSTRACA 

a\.     Free-living  or  parasitic  inhabitants  of  the  sea  or 

of  fresh  water. 
61.     2  pairs  of  maxillae. 

ci      Mandible  without  palp  ;  4  or  more  pairs 
of  foliate  swimming  legs  behind  maxillae 
[Phyllopoda]. 
d\.     With  10  to  40  pairs  of  legs       .        .   Sranchiopoda 

(Ex.  Branchipus) 

eZ2-     With  4  to  6  pairs  of  legs  .        .        .          Cladocera 

(Ex.  Daphnia) 

Co.     Mandible  with  leg-like  palp  ;  only  2  pairs 

of  appendages  behind  maxillae      .        .          Ostracoda 
bo.     Only  1  pair  of  maxillae,  followed  by  4-5  pairs 
of  bifid,  oar-like  feet ;  often  deformed  as  a 
result  of  parasitism      .         .        .         ...  Copepoda 

(Water-fleas) 

a2.  Sessile  marine  animals,  whose  body  is  surrounded 
by  a  usually  calcified  mantle  ;  6  pairs  of  tendril- 
like  feet Cirripedia 

(Barnacles) 

Key  to  the  principal  families  of  Cladocera,  to  which  group  Daphnia 
belongs  :  — 

a\.     Body  enclosed  in  a  bivalve  shell ;  mandibles  trun- 
cate below  ;  maxillae  distinct,  spiny. 
61.     6    pairs    of    similar,     foliaceous,     distinctly 
branchiate  feet ;    swimming  antennas  with 
2  unequal  rami ;  intestine  straight    .  .        .  Sididce 

52.     5  (or  6)  pairs  of  feet,  the  anterior  pair  more 
or  less  prehensile  and  destitute  of  branchiae. 
GI.     Rami  of  antennae  3-  and  4-jointed ;    5 
pairs  of  feet,  the  last  with  a  curved 
appendage  guarding  the  branchial  sac  ; 
antennules  of  the  female  sort,  1-jointed         Daphnidce 


132 


ZOOLOGY 


C2.     6  pairs  of   feet ;    antennules  elongated, 

many-jointed •    Bosminulce 

C3.     Antennae   with  both  rami  3-jointed ;  in- 
testine convolute  .....  Lynceidce 
0,2-     Body  wholly  or  nearly  destitute  of  a  bivalve  shell ; 
feet  not  branchiate,  spiny  ;    abdomen   curved, 
ending  in  two  long  stylets   .....     Polyphemidce 


CHAPTER   IX 

THE   EARTHWORM   AND   ITS   ALLIES 

Relationships. — :  Earth  worms1  belong  to  an  order  of 
Annelids  known  as  Oligochieta.2  This  group  is  distin- 
guished by  a  prevailingly  non-marine  life,  by  the  absence 
of  parapodia,  by  few  bristles,  and  by  the  absence  of  tenta- 
cles, palps,  cirri,  and  gills.3 

Habits.  —  Earthworms,  as  the  name  implies,  are  inhabit- 
ants of  the  ground,  through  which  they  burrow  and  in 


FIG.  122.  —  Flash-light  photograph  of  earthworm  and  slug  crawling  on  a  pave- 
ment at  night.    Photo,  by  D.  and  S. 

1  There  are  not  very  many  kinds  of  terrestrial  Oligochseta.     The  prin- 
cipal American  species  may  be  distinguished  with  the  aid  of  the  key  given 
in  the  Appendix  to  this  Chapter. 

2  (JXfyos,  few  ;  xa^T77:  hair. 

8  The  Oligochreta  exhibit  two  principal  subdivisions  ;  the  first  of  which 
includes  terrestrial  species  of  the  single  family  Lumbricidae,  and  the 
second  various  aquatic  families,  —  a  key  to  which  is  given  on  page  144. 


134  ZOOLOGY 

which  they  gain  their  food.  They  sometimes  come  to  the 
surface  at  night  in  search  of  companions  and  food  (Fig. 
122).  Even  during  the  day  in  rainy  weather  they  extend 
the  anterior  end  of  the  body  out  of  their  burrows.  Earth- 
worms, found  on  the  surface  at  other  times,  have,  for  the 
most  part,  been  parasitized  by  a  fly,  and  are  in  consequence 
weak  or  dying.  During  the  daytime,  if  the  surface  mois- 
ture permits,  they  lie  near  the  mouth  of  their  burrows, 
probably  for  the  sake  of  the  sun's  warmth.  In  this  posi- 
tion they  can  be  seen  by  looking  down  into  the  holes.  At 
such  times  they  are  often  caught  by  birds.  In  dry  weather, 
or  when  the  ground  is  freezing,  earthworms  burrow  deep 
to  a  moist  stratum,  or  to  below  the  frost  line,  and  hiber- 
nate there. 

Food.  — Earthworms  are  omnivorous.  As  they  burrow 
through  the  ground,  the  earth  is  taken  into  the  alimentary 
tract,  and  the  digestible  particles  are  dissolved  out  and 
absorbed  as  food.  Earthworms  can,  however,  be  fed  upon 
green  and  dead  leaves,  decaying  wood,  seedlings,  bits  of 
flesh,  and  even  filter  paper.  Earthworms  have  the  habit 
of  dragging  into  their  burrows  leaves  which  they  intend 
to  devour.  There  the  leaves  are  moistened  with  a  fluid 
excreted  by  the  worm.  This  fluid  partially  digests  the 
food.  After  being  taken  into  the  alimentary  tract,  the 
food  reaches  an  organ  of  the  canal  known  as  the  gizzard. 
This  part  has  thick  muscular  Avails,  and  contains  in  its 
cavity  small  stones ;  by  the  action  of  both  the  muscular 
gizzard  and  the  small  stones,  the  food  is  ground  up  in 
much  the  same  way  as  are  the  grains  of  corn  by  the  aid  of 
stones  in  the  gizzard  of  a  hen. 

Resistance  and  Regeneration.  —  The  capacity  which  earth- 
worms possess  of  resisting  certain  untoward  conditions  is 


THE  EARTHWORM  AND  ITS  ALLIES  135 

very  great.  Thus  they  may  be  kept  for  months  in  a 
moist  vessel  without  food,  or  with  only  filter  paper,  with- 
out starving.  On  the  other  hand,  they  die  in  a  dry  atmos- 
phere in  a  few  hours,  whereas  they  may  be  submerged  in 
water  for  several  days  without  injury.  Very  remarkable  is 
their  power  of  healing  after  injury.  If  an  earthworm  be 
cut  in  two  near  the  middle,  and  the  halves  be  kept  under 
favorable  conditions,  each  half  may  develop  its  missing 
organs  so  that  two  complete  worms  will  result.  The 
anterior  half  of  one  worm  may  be  attached  to  the  hinder 
end  of  a  second  worm  by  the  cut  edges,  owing  to  the 
fact  that  the  cut  edges  grow  together.  This  operation 
is  called  grafting. 

Economics.  —  Earthworms  are,  to  a  certain  extent,  in- 
jurious to  vegetation,  since  they  eat  tender  seedlings  and 
roots,  but,  on  the  other  hand,  they  are  almost  indispensable 
to  agriculture.  Their  burrows  permit  rain  to  percolate 
deep  into  the  ground,  instead  of  running  off  on  the  sur- 
face. They  keep  the  soil  loose,  facilitating  the  penetration 
of  the  roots  of  plants.  The  earth  that  passes  through 
their  bodies  is  ejected  on  the  surface  of  the  ground  near 
the  openings  of  their  burrows,  and  is  called  a  "  casting." 
By  means  of  castings  the  deeper-lying  earth  is  brought  to 
the  surface,  and  the  surface  layer  of  rich  earth,  called 
"  vegetable  mould,"  is  in  this  way  increased  in  thickness 
by  additions  to  its  upper  surface.  The  thickness  of  the 
layer  of  mould  which  the  castings  of  one  year,  if  uniformly 
spread  out,  would  make  has  been  estimated  by  Darwin  to 
be  in  England  about  two-tenths  of  an  inch.  Most  of  these 
castings  are  merely  taken  from  the  deeper-lying  mould, 
but  they  are  enriched  by  the  intestinal  secretions  in  pass- 
ing through  the  body  of  the  worm.  These  intestinal  secre- 


136  ZOOLOGY 

tions  are  said  to  have  the  power  of  slowly  dissolving  sand 
and  thus  of  turning  it  into  soiL  Darwin  says,  "  It  is  a 
marvellous  reflection  that  the  whole  of  the  superficial  mould 
over  any  smooth  expanse  has  passed,  and  will  again  pass, 
every  few  years,  through  the  bodies  of  worms.  The  plough 
is  one  of  the  most  ancient  and  most  valuable  of  man's 
inventions,  but  long  before  he  existed  the  land  was,  in 
fact,  regularly  ploughed,  and  still  continues  to  be  thus 
ploughed,  by  earthworms;" 

The  group  to  which  earthworms  beloeg  is  closely  related 
to  that  which  includes  Nereis  of  the  seashore.  They  are 
both  ringed  worms  or  Annelids.1':  But  whereas  Nereis  and 
its  allies  have  parapodia  provided  with  numerous  bristles, 
the  earthworm  has  no  parapodia,  and  only  a  few  bristles 
on  each  segment.  The  group  to  which  Nereis  and  its 
allies  belong  is  called  (see  Chapter  X)  Polychseta,  and 
the  group  to  which  the  earthworm  belongs  is  appropriately 
named  Oligochceta. 

The  aquatic  Oligochaeta2  are  among  the  commonest 
inhabitants  of  ponds  and  ditches,  living  sometimes  in  the 
mud  and  sometimes  at  the  surface  of  the  water. 

Tubifex3  is  common  in  slow-running  brooks,  and  lives 
in  the  mud  of  the  bottom,  forming  tubes  in  it.  The 
thread-like  bodies  of  the  worm  are  stretched  up  beyond 
the  surface  of  the  mud  and  wave  in  the  water  in  graceful 
undulations.  Often  the  worms  are  so  numerous  that  their 
reddish  color  gives  a  decided  tinge  to  the  bottom.  They 
thrive  well  in  fresh- water  aquaria. 

1  Annulus,  a  little  ring. 

2  A  key  for  the  determination  of  the  principal  families  of  aquatic  Oligo- 
chseta  is  given  in  the  Appendix  to  this  Chapter,  page  144. 

3  tubus,  tube  ;  /acere,  to  make. 


THE  EARTHWORM  AND  ITS  ALLIES 


137 


Dero1  is  very  common  on  the  surface  of  ponds,  particu- 
larly in  the  midst  of  duck-weed  (Lemna),  the  leaves  of 
which  it  cements  together  to  form  a  floating  tube  in  which 
it  lives,  and  by  which  it  is  accompanied  in  all  its  migra- 


FIG.  123.  —  Dero,  the  duck-weed  worm.  Enlarged.  After  Reighard.  The 
lettering  is  as  follows :  or.,  mouth;  phx.,  pharynx;  oe.,  O3sophagus;  sg.  o., 
segmental  organ ;  in.,  intestine;  pav.,  pavilion  or  tunnel;  dg.  app.,  finger- 
like  appendages.  From  Reighard. 

tions.  Dero  can  also  be  told  by  the  sort  of  funnel  at  the 
hinder  end  of  the  transparent  body,  from  the  margins  of 
which  finger-like  filaments  arise  which  aid  in  respiration 
(Fig.  123). 

Nais2  does  not  construct  tubes,  and  it  has  no  respiratory 


to  skin  (=  flay). 


a  water-nymph. 


138 


ZOOLOGY 


filament  at  the  hinder  end  of  the  body  (Fig.  124).     It  also 
has  eyes ;  while  Dero  has  none.     Both  Dero  and  Nais  have 

the  interesting  habit 
of  reproducing  by 
dividing  the  body 
transversely.  In  the 
middle  of  the  body 
tentacles  begin  to 
arise,  a  new  mouth  is 
formed,  and  the  worm 
constricts  into  two. 
Indeed,  sometimes 
several  new  heads  may 
be  forming  in  the 
midst  of  a  single 
worm.  This  habit  is 
of  advantage  not  only 
in  multiplying  the 
number  of  individuals 
of  the  species,  but  also 
For  if,  by  chance,  the  larva  of 


FIG.  124.  — Nais:  a,  mouth;  b,  anus;  c,  intes- 
tine.    From  Leunis. 


as  a  means  of  protection, 
the   water-beetle    Dytiscus    seizes  a  Nais 
and  bites  it  in  two,  the  part  which  escapes 
can  go  on  developing  new  individuals. 

The  slow-moving,  burrowing  habit  of 
the  earthworm  has  led  to  a  nearly  complete 
absence  of  such  appendages  as  Nereis 
possesses.  There  are  other  ringed  worms 
in  which  the  burrowing  habits  have  led  to 
a  loss  even  of  the  segments  in  the  adult. 
This  is  the  case  in  the  group  Gephyrea.1 

1  ytyvpa,  bridge  ;  because  they  were  once  considered  to  bridge  the  gap 
between  holothurians  and  worms. 


.  —  Phasco- 
,  Gephy- 
rean.  One-fourth 
nat.  size.  From 
Leunis. 


THE  EARTHWORM  AND  ITS  ALLIES 


139 


anksek 


This  group  contains  several  rather  rare  animals.  One 
of  the  commonest  is  Phascolosoma,1  which  is  a  tough  but 
smooth-skinned,  cigar-shaped  worm,  which  one  can  dig  up 
on  our  sandy  beaches  (Fig.  125).  One  end  is  pointed  ; 
from  the  other  a  great  proboscis 
terminating  in  tentacles  surround- 
ing a  mouth  can  be  extruded. 
Another  species  found  on  our 
beaches  after  a  storm,  something 
like  a  small  cucumber  in  shape  and 
size,  has  a  row  of  bristles  at  each 
end,  indicating  its  relationship 
with  the  bristle-bearing  worms. 
This  species,  Echiurus,2  is  seg- 
mented when  young  like  Nereis, 
but  eventually  it  loses  its  seg- 
mentation (Fig.  126).  Several 
species  of  Sipunculus  are  edible, 
and  are  held  in  esteem  by  the 
Chinese.  . 

To  the  account  of  the  Oli- 
gochaeta  above  given  may  be 
added  some  statements  concern- 
ing a  group  of  annelids  of  very 
different  appearance.  The  leeches, 
or  "blood-suckers,"  are  flattened 
worms,  which,  like  the  earthworm, 
show  metamerism ;  that  is,  there  is  a  repetition  of  the  in- 
ternal organs.  They  are  also  segmented ;  that  is,  the 
body  has  external  rings,  although  they  may  be  obscure. 
One  segment  does  not,  however,  as  in  the  earthworm, 


FIG.  126.  —  Echiurus.  About 
one-half  nat.  size,  prob., 
proboscis;  ant. set., anterior 
setae;  post,  set.,  posterior 
setae.  After  Greef,  from  Par- 
ker and  Haswell's  "  Text- 
book." 


1  </><£<r/co;Xos,  sac  ;  aw/Lea,  body. 


2  c%is,  adder  ;  oupci,  tail. 


140 


ZOOLOGY 


correspond  with  one  metamere,  but  there  are  three,  four, 
or  five  segments  to  a  metamere.  Leeches  have  no  para- 
podia  and  no  bristles;  but  they  have  a  sucking  disk  at 
the  posterior  end  of  the  body  for  the  purpose  of  adhesion 
(Fig.  127).  They  usually  have  a  smaller,  anterior  sucking 
disk  around  the  mouth,  which  may  or  may  not  be  provided 
with  teeth,  for  the  purpose  of  cutting  through  the  skin. 
When  there  are  no  teeth,  the  pharynx  is  protrusible, 
forming  a  proboscis.  With  a  few  exceptions,  all  leeches 


FIG.  127.  —  Clepsine,  the  flat  blood-sucker.    Ventral  view.    Posterior  sucker  at 
left.    Nat.  size.    From  life.     Photo,  by  E.  R.  D. 

live  in  water  ;  but  in  Ceylon  there  is  a  land  leech  which 
lives  in  foliage  and  attacks  man  and  other  animals.  Other 
leeches  may  live  in  damp  places  at  a  considerable  distance 
from  water.  Leeches  suck  the  blood  of  fishes  and  other 
aquatic  animals.  Certain  kinds  devour  worms,  insects,  and 
other  small  creatures. 

The  commonest  of  the  larger  blood-suckers  of  our  waters 
is  Nephelis,1  which  is  not  distinctly  segmented.  It  varies 
from  black  to  slate  color,  arid  is  sometimes  striped  or 
spotted.  It  lives  in  running  water,  in  ditches,  and  ponds. 

,  wife  of  Athamas. 


THE  EARTHWORM  AND   ITS  ALLIES 


141 


Clepsine1  is  a  very  flat  and  broad  leech,  which  is 
common  under  floating  wood.  It  feeds  on  snails  and 
creeps  like  the  inch-worm.  The  female  carries  its  young 
attached  to  its  under  surface  (Fig.  127). 


FIG.  128.  —  Pedicellina  americana,  an  endoproctous  bryozoan.    A  colony, 
magnified  15  diams.    Photo-  of  living  animals  by  W.  H.  C.  P. 

Possibly  allied  to  the  Gephyrea  is  the  group  of  Bryozoa,2 
or  moss-animals.  These  are  noteworthy  from  the  fact  that 
they  are  compound,  many  individuals  budding  off  from  one 
another,  as  in  plants.  They  are  found  abundantly  both  in 
the  sea  and  in  fresh  water.  Two  main  groups  are  dis- 

1  From  K\<?7rra>,  to  steal.  2  fiptov,  moss  ;  ^or,  animal. 


FIG.  129.  —  Bugula  turrita,  a  marine   ectoproct.     A  colouy,  magnified   1.5 
diams.    Photo,  of  living  animals  by  W.  H.  C.  P. 


r 


FIG.  1I>0.  —  Plumatella  poh/morpha,  a  fresh-water  ectoproct,  magnified  1.5 


APPENDIX    TO    CHAPTER    IX 


143 


tinguislied,  the  Endoprocta  (Fig. 
128),  iii  which  the  individual  consists 
of  a  long  stalk  and  a  "  head "  or 
body  proper ;  and  the  Ectoprocta 
(Figs.  129-131),  usually  without 
such  a  stalk.  The  Ectoprocta  are 
the  prevailing  type.  The  marine 
species  form  lace-like  mats  on  sea- 
weed or  stand  up  as  branching,  bushy 
colonies  (Fig.  129).  Some  of  the 
fresh- water  forms  make  loose,  antler- 
like  colonies  (Fig.  130),  while  others 
lie  on  the  surface  of  a  more  or  less 
spherical  mass  of  jelly  which  they 
have  themselves  secreted  (Fig.  131). 


FIG.  131.  —  Pectinatella  magnified,  a  dense  complex  of  colonies,  growing  upon 
a  stick.  Each  star-shaped  group  represents  a  single  colony.  One-half  uat. 
size.  Photo,  of  living  mass  by  W.  H.  C.  P. 


APPENDIX   TO   CHAPTER   IX 


KEY    TO    THE    PRINCIPAL    SPECIES    OF    EARTHWORMS    OF    THE 
UNITED    STATES 

a\.  Clitellum  begins  on  segment  xiii  or  xiv ;  $  pore, 
on  segment  xviii  or  xix  ;  2  gizzards  in  segments 
v  and  vi. 


61.  2  dorsal  vessels ;  lives  in  soil  of  prairies 

62.  1  dorsal  vessel ;  lives  in  river-bottom  land 

a-2.     Clitellum  does  not  begin  in  front  of  segment  xviii ; 
$  pore  on  segments  xii  and  xiii,  or  (usually)  xv. 
61.     Prostomium  incompletely  divides  buccal  lobe 
[genus  Allolobophora]. 


( Diplocardia 
\  communis 
D.  riparia 


144  ZOOLOGY 

d.  Tubercles  on  segments  xxviii-xxxi ;  ill- 
smelling  ;  purple-banded  ...  A.  fcetida 

c-2.     Tubercles  on  segments,  xxxi  and  xxxiii  .        A.  cattyosa 

c'3.     Tubercles    on    segments    xxvii,    yxviii ; 

color  reddish  brown    ....          A.  tumida 

c4.     Tubercles  on  segments  xxiv-xxx  ;  about 

100  segments        .....  A.  parva 

65.     Tubercles  on  segments  xxviii-xxx  .        A.  subrubicunda 

c6.     Tubercles  on  segments  xxix-xxxi  (occa- 
sionally xxix,  xxx);    number  of  seg- 
ments, 150    .         .         .         .         .        .  A.  rosea 

bz.     Prostomium  completely  divides   buccal  lobe 
[genus  Lumbricus]. 

Ci.  Tubercles  on  segments  xxviii-xxxi ;  red- 
brown  or  purple  ;  about  120  segments .  L.  mbellus 

c2.     Tubercles    on    segments    xxxiii-xxxvi ; 

number  of  segments,  180  L.  herculeus 

KEY    TO    THE    PRINCIPAL    FAMILIES    OF    AQUATIC    OLIGOCH^STA 

«i.     Dorsal    blood-vessels  visible  only   in  the  anterior 

part  of  the  body  ;   farther  back,  as  intestinal 

sinus,  disappearing  underneath    the    intestinal 

glands          .        .        .       '.""'.        •        •        •     Enchytrceidas 

a*.     Dorsal  blood-vessels  running  on  top  of  food  canal 

and  visible  throughout  its  entire  length. 
61.     In  each  segment,  except  the  first,  contractile 

lateral  blood-vessels Lumbriculidas 

b».     Lateral  vessels  contractile  only  in  anterior 

segments. 

Ci.  Dorsal  and  ventral  vessels  united  in  each 
segment,  except  in  the  first  5,  by  2 
lateral  vessels  .  .  .  .  Tubiflcidce 

(Ex.  Tubifex) 

c2.     Dorsal  and  ventral  vessels  united  in  each 

segment  by  a  lateral  vessel  .        .        .  Naidw 

(Exs.  Nais,  Dero) 


CHAPTER   X 

NEREIS   AND  ITS   ALLIES 

NEREIS1  is  one  of  the  commonest  worms  found  on  our 
seacoast.  It  occurs  in  sandy  or  muddy  beaches,  at  or 
below  low-water  mark,  especially  where  tidal  currents  flow 
swiftly.  It  inhabits  burrows,  which  it  makes  in  the  sand 
and  lines  with  a  mucilaginous  secretion  to  bind  together 
the  walls  of  sand  or  mud.  At  certain  seasons  of  the  year, 
during  the  breeding  season,  these  worms  may  be  found 
swimming  near  the  surface  of  the  sea. 

Nereis  lives  on  both  plant  and  animal  food.  To  capture 
its  prey  it  thrusts  out  a  long  proboscis,  provided  with  two 
powerful  jaws.  The  thrusting  out  consists  essentially  of  a 
rolling  inside  out,  —  just  as  the  finger  of  a  glove  may  be 
rolled  inside  out.  When  the  proboscis  is  rolled  in  again, 
the  jaws,  retaining  their  grip  on  the  food,  carry  it  into  the 
food  canal.  While  many  kinds  of  small  animals  serve 
Nereis  as  food,  it  is  itself  devoured  by  various  fishes  which 
dig  it  out  of  the  sand  or  capture  it  when  it  swims  free  at 
night  or  during  the  breeding  season.  Such  a  favorite  with 
fishes  naturally  makes  excellent  bait,  and  is  well  known  to 
fishermen  under  the  name  "clam-worm"  or  "sand-worm." 

Nereis  is  distinguished  by  the  fact  that  its  segments  are 
numerous  and  nearly  all  alike,  and  bear  appendages  of 
similar  form.  The  single  pair  of  jaws  on  the  proboscis  is 

,  daughter  of  Nereus,  one  of  the  Nereids,  or  sea-nymphs. 
L  145 


146  ZOOLOGY 

characteristic;  and  the  four  eyes  on  top  of  the  head,  com- 
bined with  two  antennae  and  two  palps,  serve  to  determine 
its  family  with  precision.  The  par  apod  ia  have  a  dorsal  and 
a  ventral  cirrus.  The  commonest  species  on  the  coast  of 
New  England  and  in  Long  Island  Sound  is  Nereis  virens,1 
which  grows  to  a  length  of  thirty  centimetres.  Its  color  is 
dull  green  to  bluish  green,  and  iridescent.  The  gills  on  the 
parapodia  are  green  at  the  head  end,  but  farther  back  they 
become  bright  red,  owing  to  the  blood  which  flows  through 
them.  This  species  lives  in  northern  seas,  and  is  found  on 
the  coasts  of  Great  Britain,  Norway,  Labrador,  and  south 


FIG.  132.  —  Euglycera.     One-half  natural  size.    Photo,  by  W.  H.  C.  P. 

to  Long  Island  Sound.  South  of  Long  Island  Sound  the 
commonest  species  is  Nereis  limbataf1  which  grows  to  a 
length  of,  at  'most,  only  fifteen  centimetres,  and  is  of  a  dull 
brown  or  bronze  color.  This  species  is  found  as  far  south 
as  South  Carolina. 

Often  associated  with  Nereis  in  sandy  beaches  is  a  large, 
strong,  flesh-colored  worm,  pointed  at  both  ends,  so  that  the 
head  is  not  nearly  as  evident  as  in  Nereis,  and  having  small 
appendages,  so  that  it  looks  smooth  like  an  earthworm.  This 

1  Green.  2  Bordered  or  edged. 


NEREIS  AND  ITS  ALLIES  147 

is  Euglycera.1  Its  proboscis  has  four  jaws,  situated  at  the 
corners  of  a  square,  instead  of  two  as  in  Nereis.  The  pointed 
head  and  powerful  writhing  muscles  enable  the  animal  to 
burrow  with  great  rapidity  (Fig.  132). 

A  second  kind,  Autolytus,2  is  a  small  animal  which 
lives  in  little  tubes  attached  to  algse  or  hydroids  (Fig. 
133).  The  parapodia  at  the  anterior 
half  of  the  animal  are  different  from 
those  at  the  posterior  half,  for  the 
latter  are  large  and  fitted  for  swim- 
ming. Eventually  one  of  the  middle 
segments  of  the  body  becomes  trans- 
formed into  a  head,  with  eyes  and 
tentacles,  then  the  whole  of  the  hinder 
half  breaks  off  spontaneously.  The 
newly  formed  head  is  now  the  head 
end  of  the  new  individual.  This 
individual  leads  a  different  kind  of 
life  from  the  half  which  remains  in 
the  tube,  for  it  swims  freely  in  the 
water.  The  separated  individuals  are 
either  male  or  female,  whereas  the  part 
which  lives  in  the  tube  never  pro-  FlG.  133.  -Autolytus, 

duces  eggS,  but  merely  forms  a  new  representative  of  a  fam- 
,  .,  '.  ,,  ,,  ,  ,  -T  .  _  ily  of  Polychfeta  in 

tail  every  time  the  old  tail  is  cut  oft  which  the  animal  buds 
to  form  a  sexual  individual.  off  male  or  female  in- 

;%.,,.,  0  dividuals  from  its  hinder 

A    third     kind,     Lepidonotus3     is    'end.    bud,  head  of  the 
characterized    by   the    possession    ot      budded  individual.  After 

A.  Agassiz. 


1  e&,  typical  ;   FXike/ra,  a  woman's  name,  also  applied  to  a  family  of 
Polychseta.     Euglycera  means  typical  of  the  family  Glyceridae. 

2  atfr6s,  self  ;  Xtfw,  to  separate  ;  hence,  self-separating. 

3  Xe7r/s,  scale  ;  J/WTOS,  back. 


148 


ZOOLOGY 


FIG.  134.— Lep- 
idonotus,  the 
scaled  worm. 
Nat.  size . 
Photo,  by  W. 
H.  C.  P. 


a  double  row  of  scales  covering  over  the  back  (Fig.  134). 
These  scales  are  outgrowths  of  the  dorsal  part  of  the 
parapodia,  and  serve  for  respiration.  In  allied 
genera  the  scales  are  covered  with  bristles, 
which  may  be  so  very  long  and  abundant  as 
to  hide  the  scales.  They  produce  a  brilliant 
iridescence.  One  of  these  worms  with  the 
great  bristles  may  be  several  inches  long  and 
relatively  broad,  and  is  commonly  known  as 
the  "sea-mouse  "  (Fig.  135).  Both  Lepido- 
notus  and  the  sea-mouse  occur  in  out-of-the- 
Avay  places,  —  crevices  of  rocks  at  low  tide 

or  fairly  deep 
water,  —  so  that 
they  are  not  com- 
monly seen  at  the 
seashore. 

The  sedentary  Polychaeta  are 
mostly  smaller  and  less  familiar 
animals  than  the  free-living 
Polychseta,  but  they  have  an 
interest  for  us  in  showing  how 
greatly  modified  an  organism 
becomes  when  it  takes  on  a 
sedentary  life.  Its  swimming 
appendages  become  rudimen- 
tary; its  eyes  are  usually  lack- 
ing; there  is  no  protrusible 
proboscis  armed  with  powerful 
jaws ;  the  gills  become  grouped 
almost  exclusively  about  the 
™^"£STSe-  "PPer  end  of  the  body,  where 


NEREIS  AND   ITS  ALLIES 


149 


they  can  be  thrust  out  of  the  tube  ;  the  mouth  comes  to  lie  at 
the  bottom  of  a  funnel,  which  receives  as  food  small  parti- 
cles floating  in  the  water;  even  the  segmentation  of  the 
body  becomes  lost  at  the  hinder  end  of  the  animal ;  in  a 
word,  all  those  organs  which  are  useful  for  active  carnivo- 
rous life  have  become  re- 
duced to  the  bare  needs  of 
a  quiet  herbivorous  life. 


FIG.  l.'JG.  —  Amphitnte,  removed  from  its 
tube.   Nat.  size.   Photo,  by  W.H.C.P. 


FIG.  137.  —  Polycirrus,  the  blood 
spot.  Nat.  size.  Photo,  by 
W.  H.  C.  P. 


The  first  of  these  sedentary  worms  that  we  have  to  con- 
sider is  not  completely  modified  from  the  type  found  in 
free-living  species. 

Cirratulus 1  lives  in  tubes  in  mud  or  sand.  It  is  yellow 
1  From  cirrus,  curl,  ringlet. 


150 


ZOOLOGY 


or  orange  in  color,  and  has  long  cirri,  which,  arising  from 
nearly  every  segment,  reach  out  in  all  directions.  These 
function  as  gills,  and  when  broken  off  may  remain  alive 
for  days. 

Clymenella,1  which  looks  like  a  reddish,  jointed  straw, 
builds  tubes  of  agglutinated  sand,  and  has  a  serrated,  funnel- 
shaped  tail  end.  Its  parapodia  are  very  small  (Fig.  139). 


FIG.    138.  —  Tube  of    Cistenides.     Nat.   size. 
Photo,  by  W.  H.  C.  P. 


Fio.139. — Clymenella,straw- 
worm.  The  anterior  seg- 
ments only  are  shown. 
After  M.  Lewis. 


Amphitrite2  (Fig.  136)  builds  firm  tubes  of  sand.  From 
the  head  spring  numerous  tentacles  and  three  pairs  of  blood- 
red  gill-tufts.  The  body  is  large  anteriorly  but  becomes 
slender  behind,  where  there  are  no  bristles.  Allied  to 
Amphitrite  are  a  large  number  of  common  worms  found 
on  our  coast.  Polycirrus,  or  the  blood-spot  (Fig.  137),  is 
somewhat  smaller  than  Amphitrite  and  characterized  by  a 

1  Diminutive  of  KXv^pi?,  daughter  of  Oceanus. 

2  'A/j.<f>iTpiTi],  wife  of  Neptune,  goddess  of  the  sea. 


NEREIS  AND  ITS  ALLIES 


151 


uniform  crimson  color  and  a  large  number  of  cirri  massed 
at  the  head.  The  tubes  made  by  some  of  the  Terebellidse 
are  very  beautiful.  The  tube  of  Cistenides  (Fig.  138)  is 
found  in  the  sand  under  stones  and  is  composed  of  grains 
of  sand  cemented  together  and  regularly  arranged  so  as  to 
form  a  firm  wall. 

Finally,  Serpula1  secretes  crooked,  round  calcareous 
tubes,  which  may  be  found  adhering  to  stones  near  low 
water  (Fig.  140). 
From  the  mouth  of 
the  tube  the  head, 
with  its  tentacles, 
may  be  protruded, 
but  it  quickly  re- 
tracts from  danger 
and  closes  the  open- 
ing of  the  tube  as  a 
marine  snail  does  its 
shell,  by  means  of  an 
operculum  or  lid. 

Some  worms  have 
gained     a      parasitic 


FIG.  140.  —  Serpula  tube  on  a  bit  of  oyster 
shell  that  is  perforated  by  the  boring  sponge. 
The  tube  lies  in  the  centre  of  the  figure. 
Nat.  size.  Photo,  by  W.  H.  C.  P. 


a 

habit,  and  in  con- 
sequence have  become  much  modified  in  form  and  struc- 
ture. Sucli  is  the  case  with  some  of  the  round- 
worms.  Some  of  these  are  thread-like,  live  in  springs 
or  pools,  and  are  regarded  by  the  uninitiated  as  animated 
horse-hairs.  Others  are  spindle-shaped,  as  for  example 
the  "  vinegar  eel  "  and  the  round- worms  that  are  common 
in  stagnant  water.  Others  live  in  the  food  canal,  as  for 
example  the  stomach  worm  (Ascaris)  of  the  horse  and  the 
1  Diminutive  of  serpens,  serpent. 


152 


ZOOLOGY 


B 


FIG.  141. — Trichina.  A,  encysted  form  in  muscle  of  pork;  B,  female; 
(7,  male ;  bh,  envelope  of  cyst ;  cy,  cyst ;  de,  male  duct ;  e,  embryos ;  /,  fat 
globules;  h,  testis;  mf,  muscle  fibre;  oe,  pharynx;  ov,  ovary;  no,  opening 
to  egg  duct;  zh,  cell  masses  in  intestines.  After  Glaus. 


NEEEIB  AND  ITS  ALLIES 


153 


pin-worm  of  man.  Others  still  penetrate  into  the  mus- 
cles, and  cause  great  pain  and  often  death.  Such  is  the 
pork- worm,  Trichina,1  which  gets  into  man  through  un- 
cooked pork,  multiplies  in  the 
food  canal,  migrates  in  great 
numbers  into  the  muscles  and 
encysts  itself  there  (Fig.  141). 
Another  group  which  is 
largely  parasitic  is  that  of  the 
flatworms.  Some  flatworms 
live  free  in  ponds.  They  will 
be  found  abundantly  among 
plants  taken  from  small  ponds 
in  the  summer  and  autumn,  and 
are  commonly  known  as  Pla- 
naria2  (Fig.  142).  They  may 
be  recognized  not  only  by  their 
flattened  form,  but  also  by  a 
curious  proboscis  which  pro- 
trudes from  the  middle  of  the 
under  side  of  the  body  and  bears 
a  mouth  at  its  tip.  These 
creatures  have  a  marvellous  FKi.  142._Species  of  fresh-water 

power   of    regeneration,   SO   that        Planaria.        1,     Dendrocoelum 

every  piece  into  which  a  worm 

is  cut  will  reproduce  an  entire 

one  (Fig.  143).      If  the  worm 

is  mutilated  but  not  wholly  cut  in  two,  bizarre  forms  may 

result  by  a  modified  tendency  to  regenerate  (Fig.  144). 

Other    flatworms    are  parasitic,  such  as  the  liver-fluke 
of  the  sheep  (Fig.  145).      This  destructive  parasite  has  a 


lacteum,  cream  color;  2,  Pla- 
naria maculata ;  3,  head  end  of 
same  to  show  light  streak. 
After  Woodworth. 


,  hair. 


2planus,  fiat. 


154 


ZOOLOGY 


complicated  series  of  stages  to  go  through  before  it  be- 
comes adult.  Thus  the  flukes  in  the  liver  of  the  sheep 
produce  eggs  which  develop  into  embryos.  These  em- 
bryos get  out  of  the  liver  into  the  food  canal,  and  thence 


00' 


u 


ec.10. 


"J  Marcti13.Apr.4-. 
Jan.25.  FAS.  Feb.17 


Jec.W. 


Jan.25. 


Feb.5. 


FIG.  143.  —  Showing  results  of  cutting  Planarians  into  two  pieces;  the  pieces 
develop  into  entire  animals.     After  Morgan. 

to  the  exterior.  If  they  are  deposited  near  a  pool  of 
water,  they  may  develop  further,  otherwise  they  must 
die.  In  the  water  a  ciliated  larva a  hatches  from  each 
egg,  swims  about  for  a  time  until  it  finds  a  fresh-water 
snail,  bores  into  it,  and  encysts  itself  there.  In  this 
i  Fig.  146,  A. 


NEREIS  AND  ITS  ALLIES 


155 


FIG.  144.  —  Showing  abnormal  forms 
resulting  from  mutilation  of  Pla- 
narians.  After  Van  Duyne. 


encysted  stage  the  worm  is 
known  as  a  "sporocyst," 
because  it  is  full  of  germs 
(spores)  of  a  new  genera- 
tion.1 The  spores  develop 
in  the  snail  into  curious 
organisms,  a  sort  of  second- 
ary larvae  known  as  redia.2 
The  redise  may  produce,  by 
a  kind  of  internal  budding, 
new  redise,  and  so  on  re- 
peatedly, until  at  last,  on 
the  death  of  the  snail,  or 
from  some  other  cause,  the 
last  generation  of  rediae 
produces  liver-flukes.3  The 
young  liver-flukes  wriggle  out  of  the  snail,  attach  them- 
selves to  damp  grass,  lose  their  tails,  and  encyst  them- 
selves. If  these  cysts  be  eaten  by  a 
sheep,  they  develop  in  the  sheep's 
body  into  an  adult  liver-fluke  (Fig. 
145).  Thus  the  stages  which  we  can 
recognize  in  the  liver-fluke  are :  — 


First  generation  :   egg  from  liver-fluke,  larva, 

and  adult  sporocyst. 
Second  generation  :  redia  (this  may  be  several 

times  repeated). 
Third  generation  :  "  cercaria  "  larva,  encysted 

larva,  and  adult  liver-fluke. 

1  Fig.  146,  B.  2  Fig.  146,  C. 

3  These,  while  young,  have  tails,  and  are  called 
"cercaria. 


FIG.  145.  —  Distomum, 
the  liver-fluke.  Nat. 
size.  Excr.,  excretory 
pore;  mo.,  mouth;  repr., 
reproductive  aperture ; 
sckr.,  posterior  sucker. 
From  Parker  and  Has- 
well. 


" 


156 


ZOOLOGY 


Another  flat  worm  is  such  an  abject  parasite  that  it  has 
lost  most  of  the  organs  usually  possessed  by  worms.  This  is 
the  tapeworm  (Fig.  147).  When  the  eggs  of  the  tape- 
worm are  taken  into  the  body  of  an  herbivorous  animal,  the 
embryos  develop  there  for  a  way  and  then  stop.  When 
flesh  containing  these  embryos  is  eaten  by  a  carnivorous 


FIG.  146.  —  Development  of  Distomum.  A,  ciliated  larva ;  B.  sporocyst  con- 
taining developing  rediae ;  C,  redia,  containing  a  daughter  redia  and  embryo 
liver-flukes;  D,  free-swimming,  tailed  larva  of  liver-fluke;  b.  op,  birth 
opening;  ent,  food  canal  of  redia;  eye,  eyespots;  gast,  young  redia ;  germ, 
mor,  early  stages  in  formation  of  .the  embryo  liver-fluke ;  int,  intestine  of 
larval  liver-fluke  ;  ces,  oesophagus ;  or.  su,  oral  sucker;  pap,  head  papilla  of 
ciliated  larva,  A;  ph,  pharynx;  proc,  processes  of  redia;  vent,  su,  ventral 
sucker.  After  Thomas. 

animal,  the  embryos  attach  themselves  to  the  food  canal  of 
their  host  and  form,  by  rapid  growth,  a  long  chain  of  seg- 
ments, each  of  which  is  full  of  germs.  The  chain,  or 


NEREIS  AND   ITS  ALLIES 


15' 


FIG.  147.  —  Tsenia  solium,  the  human  tapeworm.      Entire  specimen,  about 
natural  size.     Cap,  head.    After  Leuckart. 


158  ZOOLOGY 

utape,"  absorbs  fluid  food,  which  soaks  through  its  body 
wall.  As  the  segments  at  the  older  end  of  the  animal 
mature,  they  are  set  free  and  pass  out  of  the  alimentary 
tract,  to  be  picked  up,  perchance,  in  the  food  of  an  herb- 
ivorous animal  or  else  to  perish. 

The   economic  importance   of  parasitic  worms  is  very 
great.     Thus,  although  no  great  epidemics  of  the  flukes 

have  occurred  in  this  coun- 
try, a  million  sheep  are 
annually  lost  by  this  para- 
site in  Great  Britain ;  and 
in  1879  and  1880  it  was 
estimated  that  three  million 
sheep  died  annually  in 
England  alone  of  this 
parasite.  In  Buenos  Ayres, 
during  1882,  a  million 
sheep  died  of  fluke  disease. 
By  great  care  in  prevent- 
ing infection,  especially 
during  damp  seasons,  we 
may  be  able  to  prevent 

FIG.  148.— Cerebratulus,  a  cream-colored  any    SUch    disaster    in    this 
nemertean.    Head  end  at  upper  part  of  ,  . 

figure;  mouth  turned  toward  observer,  C         lWV" 

proboscis    retracted.       Instantaneous         The  group  of  Nemertini 

photograph  of  living  worm  by  W.H.C. P.  .        ni.     i    ,       .-•       n    , 

is  allied  to  the  flat  worms. 

It  includes  chiefly  marine  animals,  of  somewhat  flattened 
form  and  great  length,  even  as  great  as  thirty  metres. 
They  protrude  a  long,  slender  proboscis.  These  worms 
are  especially  abundant  in  the  sand  of  the  seashore, 
although  land  nemerteans  occur.  Cerebratulus  (Fig.  148) 
is  a  common  form  from  the  east  coast. 


APPENDIX  TO   CHAPTER  X 


APPENDIX   TO   CHAPTER   X 


159 


i 


KEY    TO    THE    MORE    IMPORTANT    FAMILIES    OF    POLYCH^TA 


a\.   Head  distinct  from  trunk  ;   proboscis  protrusible 

[wandering  Polychseta]. 
bi.    With  broad  dorsal  scales        .  ;        . 

&2-   No  scales  ;  only  one  mouth-segment. 

d.    Cirri  not  leaf-like ;    body  long  and  not 

flattened. 
d\.   Head  not  segmented. 

ci.  Jaws  composed  of  many  pieces  . 
62-    Two  powerful  jaws    . 

<?2.    Head  with  its  lobes  segmented  . 
c2.    Small  worms,  body  flattened,  cirri  evident 

«2.    Head  not  distinctly  separated  from  trunk  ;  pro- 
boscis short,  not  protrusible  ;   no  jaws  [seden- 
tary Polychseta]. 
bi.    Gills,  when  present,  arise  either  from  almost 

all,  or  else  the  middle  segments. 
Ci.    Body  not  separated  into  various  regions ; 
distinct    head ;    no    antennas ;   gills    in 
form  of  elongated,  thread-like  cirri 

C2.  Body  divided  into  2  or  3  different  regions  ; 
no  antennal  cirri ;  proboscis  present ; 
no  gills  .  .  .  . 

62.    Gills  almost  always  present  and  limited  to  the 

anterior  end  of  the  body  ;  no   cirri ;    body 

divided  into  an  anterior  and  a  posterior  part. 

GI.    Gills  confined  to  the  anterior  segments  ; 

head  lobe  small ;  numerous  antennas  in 

2  bunches ;    no  antennal  cirri 

c2.  Gills  confined  to  head  ;  2  inrolled  leaves 
standing  at  the  sides  of  the  mouth 


Aphroditidce 

(Ex.  Lepidonotus) 


Eunicidas 
Nereidai 

(Ex.  Nereis) 

Glyceridce 

(Ex.  Euglycera) 

Syilidce 

(Ex.  Autolytus) 


Cirratulidce 

(Ex.  Cirratulus) 


Maldanidce, 
(Ex.  Clyuienella) 


Terebellidce 

(Ex.  Amphitrite) 

Serpulidce 
(Ex.  Serpula) 


CHAPTER   XI 

THE   SLUG  AND   ITS   ALLIES 

THE  slug  belongs  to  the  group  of  Mollusca.1  This 
group  contains  animals  which  possess  two  distinctive 
organs  —  the  foot,  by  means  of  which  locomotion  is 
effected,  and  the  mantle,  a  fold  of  skin  covering  over 
or  enclosing  a  greater  or  less  part  of  the  body.  The 
mantle  usually  secretes  on  its  outer  surface  a  calcareous 
shell.  Exceptionally,  both  shell  and  mantle  may  be 
entirely  absent  in  the  adult. 

Among  the  Mollusca,  the  slug  occupies  the  class  Gastrop- 
oda,2 characterized  by  the  possession  of  a  head,  which  bears 
feelers  and  eyes,  and  an  unpaired  foot,  situated  on  the 
ventral  surface  of  the  body  and  used  to  crawl  upon.3 
Gastropods  are  either  with  or  without  an  external  shell. 
When  the  shell  is  present,  it  is  made  of  one  piece,  that  is, 
it  is  univalve.^ 


1  mollis,  soft. 

2  yao-TT?ip,  belly,  stomach  ;  TTOUS,  foot. 

3  A  key  to  the  principal  families  of  gastropod  shells  of  the  Atlantic 
coast  of  the  United  States  is  given  in  the  Appendix,  p.  174. 

4  The  three  orders  of  Gastropoda  may  be  distinguished  by  aid  of  the 
following  key  :  — 

«i.   Breathing  by  means  of   lungs ;   no  operculum ; 

living  on  land  and  in  fresh  water     .        .         .  Pulmonata 

az.    Breathing  by  gills  ;  chiefly  marine. 

160 


THE  SLUG  AND  ITS  ALLIES  161 

Slugs  belong  to  the  group  of  air-breathing,  land-inhabit- 
ing gastropods,  or  Pulmonata.1  They  may  be  found  in 
the  spring,  summer,  and  autumn,  under  wet,  decaying 
pieces  of  wood,  under  stones  or  fruit,  in  the  grass,  on  the 
shady  side  of  fences ;  in  a  word,  in  moist,  dark  situations. 
They  especially  shun  sand,  ashes,  and  sawdust,  because 
these  substances  tend  to  dry  up  the  mucus  which  they 
secrete  over  their  body  to  retain  its  internal  fluids.  Slugs 
are  nocturnal  (Fig.  122),  hence  they  have  the  reputa- 
tion of  being  rather  rare.  *  During  the  winter  they  live 
in  the  ground  encased  in  their  own  slirne,  but  some  species 
frequent  greenhouses  in  cold  weather,  and  in  consequence 
of  this  habit  may  remain  active  all  the  year  round. 

The  food  of  slugs  consists  chiefly  of  the  green  leaves  of 
succulent  plants,  and  also  of  ripe  fruit,  such  as  apples. 
Our  largest  slug,  Limax2  maximusf  is  easily  maintained 

fti.    Gills  in  front  of  heart ;  mantle-complex  on 
anterior  side  of  intestinal  sac  ;  operculum 
constantly  present     .....    Prosobranchiata 

62-    Gills  behind  heart ;  if  shelled,  without  oper- 
culum       ......          Opisthobranchiata 

Key  to  the  principal  families  of  the  American  Pulmonata  :  — 
a\.    Eyes  at  apex  of  (usually  retractile)  tentacles. 

61.    With  external  shell ;  4  tentacles  .         .         .  Helicidce 

(Ex.  Helix) 
l)Z.    Without  external  shell .....  Limacidce, 

(Ex.  Umax) 

«2.    Eyes  on  inner  side   or  at  base   of  the    (non- 
retractile)  tentacles. 
61.    Thick  shell,  with  thick,-  often-toothed  outer 

edge Auriculidce 

(Ex.  Melampus) 

62-    Thin  shell,  with  sharp  margin      \        .         .  Limnceitlce 

(Ex.  Physa) 
1  Provided  with  lungs  ;  from  pulmo,  lung. 

,  naked  snail.  3  Largest. 


162 


ZOOLOGY 


in  captivity  by  keeping  in  a  dark  box  and  feeding  on  the 
blanched  leaves  of  cabbage.  In  captivity  one  individual 
will  sometimes  devour  another. 

Of  our  three  principal  species  of  slugs  there  may  be  first 
mentioned  Limax  maximum  which  gains  a  length  of  about 
10  centimetres  and  has  a  light  brown  color,  marked  with 
longitudinal  rows  of  black  spots  along  the  back  and  sides. 

This  species  was  almost  un- 
known in  this  country  until 
the  middle  of  the  sixties,  but 
it  is  now  widespread  through- 
out the  East.  It  has  doubt- 
less been  introduced  from  the 
continent  of  Europe,  where 
it  is  very  abundant.  Second, 
Limax  agrestis1  is  usually 
about  2.5  centimetres  long  ; 
it  varies  in  color  from  whitish 
through  gray  to  black.  It  is 
now  common  in  the  eastern 

FIG.   149. -Illustrating   the   transi-      United  States,  but  is  believed 

tion  of  form  in  the  shell  of  certain    to  have  been  introduced  from 

Opisthobranchs,  from  the  pointed  ^,  rni  .     -,      T  . 

spiral  to  the  almost  flat  plate.  The  Europe.  1  hird,  Limax  CCtm- 

genera  figured  are:    A,   Actseon;  pestris?  a   native    Species,    is 

B,  Aplustrum;    C,  Cylichna;   D,              „  ,,  ,.               , 

smaller  than  agrestis,  and 
its  tuberosities  are  not  so 


Atys;  E,  Philine ;  F,  Dolabella; 
G,  Aplysia ;  H,  Pleurobranchus. 
Drawn  to  various  scales.  From 
Cooke,  "  Mollusca." 


much  flattened  or  plate-like. 

It  occurs  widely  distributed 
east  of  the  Rocky  Mountains. 

Economically,  slugs  are  of  importance  because  at  times 
in  some  localities  they  cause  much  destruction  in  gardens 


Living  in  the  field. 


2  Living  in  open  fields. 


THE  SLUG  AND  ITS  ALLIES 


163 


and  greenhouses.  Particularly  in  Europe,  Limax  agrestis 
has  often  devastated  fields  of  young  shoots  ;  this  species 
is  especially  fond  of  bulbous  plants. 

In  the  apparent  absence  of  a  shell  the  slug  seems  to  be 
an  aberrant  gastropod.  Other  land  gastropods  —  the 
snails  —  have  an  evident 
shell.  In  Limax  the  shell 
is  reduced  to  a  thin,  horny 
plate,  embedded  in  the 
mantle.  Between  the  con- 
dition seen  in  the  snail 
and  that  in  Limax  there 
are  intermediate  condi- 
tions, in  which  the  large 
shell  is  partly  covered  by 
the  mantle,  and  others 
in  which  the  shell  has 
become  reduced  in  size. 

In    allies    of     Limax  —  in     FlG-    149«-  ~  Illustrating    the    gradual 

covering  of    the  shell    (sh)    in  certain 
a    geilUS    Called    Anon —        Opisthobranchs  by  the  epipodia  (ep)  and 

the  shell  is  reduced  to  a      raantle;  *•*>  cephalic  disc.   Drawn  to 

various  scales.    A,  Hammea;    B,  Sca- 
few      Calcareous      grains.         phander;  C,   Aplustrum;   I),  Aphysia; 

An  exactly  similar  series  ^  Philine'  From  Cooke'  "Mollus^-" 
in  the  degeneration  of  the  shell  is  found  in  certain  Opistho- 
branchs, illustrated  in  Fig.  149.  The  beginnings  of  this 
process  of  covering  the  shell  are  seen  in  many  gastropods 
in  which  the  mantle  edges  may  protrude  beyond  the 
lips  of  the  aperture,  and  are  folded  back  over  the  outer 
surface  of  the  shell.  A  more  developed  condition  is  seen 
in  species  like  Aplysia,  in  which  the  mantle  is  permanently 
reflected.1  In  Limax  the  reflected  edges  of  the  mantle 

i  Fig.  149a. 


164  ZOOLOGY 

have   permanently  grown  together.     The  reflection  of  the 
mantle  seems  to  he  of  advantage  by  affording  additional 

protection  to  the  visceral  mass. 
But  after  the  complete  over- 
growth of  the  mantle  the  shell 
seems  to  be  useless,  and  con- 
sequently degenerates. 

The  Pulmonata  are  either 
terrestrial,  like  the  slug,  or 
aquatic.  Of  the  terrestrial 


Fia.  150. -Shell  of  iielix  alboia-  pulmonates     other    than    the 

bris,  a  cQmmon  forest  snail.   Nat.  ,  s\Ucr    the    most    important    are 
size.    Photo,  by  W.  H.  C.  P.  .,        ,   , ,  TT  T     \ 

the  snails  of  the  genus  Helix.1 

Helix2  is  noteworthy,  because  it  is  richer  in  species  than 
any  other  inolluscan  genus,  since  it  contains  over  three 
thousand  species.  The  distribution  of  the  genus  is  world- 
wide. In  North  America  the  snails  are  most  abundant  in 
limestone  regions,  consequently  they  are  more  numerous 
in  individuals  in  the  South  and  West  than  in  granitic 
New  England.  One  of  the  most  interesting  species  is 
Helix  nemoralis,  a  European  form,  which  has  been  intro- 
duced into  our  country  at  Burlington,  New  Jersey,  and 
Lexington,  Virginia.  At  these  places  it  has  multiplied 
so  rapidly,  and  varied  to  such  a  degree,  that  three  hundred 
and  eighty-five  varieties  have  been  enumerated  from  an 
area,  at  Lexington,  not  over  one  thousand  feet  in  extent 
in  its  greatest  diameter3  (Fig.  151).  Any  species  of 
Helix  collected  in  large  numbers  is  apt  to  show  abnor- 
malities in  the  number  of  tentacles  and  of  eyes  upon  the 

1  £Xi£,  a  turning  round,  as  in  spire  of  snail  shell.  2  Fig.  150. 

3  See  paper  by  Professor  J.  L.  Howe,  in  American  Naturalist,  Decem- 
ber, 1898. 


THE  SLTG   AND   ITS  ALLIES 


165 


tentacles.     Besides  Helix,  a  very  abundant  cosmopolitan 
land  pulmonate  is  Pupa.1     Being  of  small  size,  it  is,  how- 


* 


FKJ.  151.  —  Helix  nsmaralix,  from  Lexington,  Va.,  collected  by  Professor  J.  L. 
Howe,  showing  variation  in  stripes.  Upper  line,  first  figure,  normal  form, 
5  stripes ;  other  figures  of  first  and  second  lines  show  reduction  of  stripes  ; 
third  line  shows  broader  (and  fewer)  stripes  (the  last  figure  is  very  dark 
and  is  poorly  reproduced).  The  shells  in  the  lowest  line  show  more  than 
five  stripes.  From  a  photograph ;  reduced  one-half. 

ever,  less  commonly  known.  It  is  found  in  woods  under 
leaves  or  in  old  stumps  and  decaying  logs,  where  it  feeds. 
The  shell  is  many  times  whorled,  and  has  a 
blunt  apex. 

Intermediate  between  the  terrestrial  and 
aquatic  pulmonates  is  the  family  Auriculidte, 
the  members  of  which  live  on  the  seashore, 
in  salt  marshes  or  on  rocks  where  they 
may  even  be  immersed  in  brackish  water 


1  A  little  girl  or  doll. 


FIG.  152.  —  Me- 
lampus,the  salt- 
marsh  snail. 
Nat.  size.  Photo, 
by  \V.  H.  C.  P. 


166 


ZOOLOGY 


at  high  tides.     One  of  the  commonest  forms  is  Melampus 
(Fig.  152),  found  among  the  roots  of  marsh  grass. 

Of  the  aquatic  pulmonates  three  genera  are  common  and 
easily  distinguishable.  Limnaea,1  the  '"  pond  snail,"  is  com- 
mon in  ditches  and  muddy  or  stagnant  ponds.  Its  shell 
runs  up  into  a  sharp  spire,  and  is  right-handed,  i.e.  hold- 
ing the  shell  so  that  its  aperture 
is  next  the  observer  and  below, 
the  aperture  is  at  the  right 
(Fig.  153).  Limnsea  crawls  over 
the  bottom,  up  the  stalks  of 
aquatic  plants,  and  on  the  sur- 

FIG.   153. -Left,    Physa    hetcro-  faCG      film     °f     Water'        During 

stropha,  the  left-handed    pond  drought    it    burrows     into     the 
snail.  Right,  Limnaea.  the  right-  i  i     i  ,-,  P 

handed  pond    snail,    with    the  lliud>  aild  cl°SeS  the  aperture  of 

apex  eroded  off  as  is  usually  the  the    shell . 
case  in  adult  shells.    Nat.  size.         -r»i_          o    i 

Photo.byW.H.c.P.  Pnysa^  has  a  smaller,    rela- 

tively stouter  shell  than  Lim- 
nsea, and  one  whose  coil  is  left-handed  (Fig.  153).  It 
lives  in  even  the  smaller  ponds  and  brooks,  and  may  be 
easily  reared  in  aquaria.  It  feeds  freely 
upon  any  kind  of  vegetable  matter. 
Physa  heterostropha  is  the  common  species 
of  the  United  States  (Fig.  153,  left). 

Planorbis  3  is  coiled  in  one  plane  like  a 
watch  spring.4  It  lives  in  a  similar 
habitat  with  Physa.  A  great  many 
species  are  distinguished  which  vary  con- 
siderably in  size.  Snails  of  this  genus 
likewise  are  easily  kept  in  the  aquarium,  and  lay  numerous 


FIG.  154.— Planorbis, 
the  flat-coiled  pond 
snail.  Nat.  size. 
Photo.byW.H.c.P. 


1  From  \Lfjivij,  a  marsh. 

2  <£0<ra,  bellows, 


3  planus,  flat ;  orbis,  circle, 

4  Fig.  154, 


THE  SLUG  AND  ITS  ALLIES  167 

eggs  encased    in    gelatinous   envelopes   adhering   to    the 
glass. 

Of  the  shells  of  marine  gastropods,  which  are  favorite 
objects  in  collections  because  of  their  beauty  and  per- 
manence, only  a  few  types  can  be  mentioned. 

Littorina1  is  an  example  of  the  entire-mouthed  proso- 
branchs.  The  commonest  form  at  most  parts  of  thj^hore- 
line  north  of  New  York  at  the  present  time  is 
littorea.2  This  is  known  in  England 
as  the  periwinkle,  and  is  there  used  as 
food.  As  its  systematic  name  implies, 
it  occurs  on  the  seashore,  which  it 
often  crowds  so  as  to  force  all  other 
species  from  it.  It  occurs  north  to 
Greenland,  and  on  the  northwestern 
European  coast.  It  has  not  always  FIG.  155.  —  Littorina  lit- 
occupied  our  shores,  but  has  been  £?£*£££ 
migrating  southward.  In  1855  Lit-  w.  H.  c.  P. 
torina  was  found  in  the  Gulf  of 
St.  Lawrence  ;  in  1869  it  was  stated  to  occur  in  Halifax  ; 
in  1870  a  few  individuals  were  found  on  the  Maine  coast ; 
during  1871  the  species  occurred  on  the  New  Hampshire 
coast ;  in  1872  one  specimen  was  found  at  Salem,  Massa- 
chusetts ;  in  1875  the  first  two  specimens  were  taken  at 
Woods  Hole,  Massachusetts,  south  of  Cape  Cocl ;  in  1880 
the  first  specimen  was  taken  at  New  Haven ;  in  1891  it 
occurred  as  far  south  as  Delaware  Bay.  Yet  at  the  present 
time  it  is  not  very  abundant  at  Cold  Spring  Harbor,  near 
the  western  end  of  Long  Island  Sound.  Persons  who  live 
on  the  coast  south  of  Cape  Cod  would  do  well  to  note  care- 
fully the  abundance  of  the  species  on  their  part  of  the 

1  Fig.  155,  2  From  Uttus,  the  seashore, 


168 


ZOO  LOG  1" 


tia)  heros. 
nat.  size. 
W.  H.  C.  P. 


(Luna- 
Two-thii-ds 
Photo,  by 


shore-line.       Besides   littorea    there    are    two    species    of 

Littorina   which    were   on  our    coast    when    records   first 

began   to    be    made.       The     species 

may  be  distinguished  by  the  circum-         ^fT~* 

stances  that  L.   littorea  has  a  black 

head   and  a  heavy  shell  of  brown  or 

olive  color.     L.  rudis 1  is  smaller,  has 

an  angle  at  the  apex  of  60°  to  70°, 

and    its    shell  varies   in   color   from 

white  to  red.      L.   palliata*  has  an    FIG.  ISG.  - 

apical   angle   of    95°,    and    a    shell 

varying  from  white  to  orange,  slate, 

or  brown. 

Natica  is  another  common  species  with  an  entire  mouth. 

It  can  be  at  once  distinguished  from  Littorina  by  the 
"  umbilicus,"  or  depression  situated  at 
the  left  of  the  mouth  and  in  the  axis  of 
the  shell  (Fig.  156).  In  the  living 
animal  the  shell  is  often  quite  envel- 
oped by  the  large  fleshy  foot.  The 
members  of  this  genus  lay  their  eggs 
in  spiral  "  collars "  made  of  aggluti- 
nated sand.  These  are  common  objects 
of  the  seashore. 

Fulgur3  is  a  good  example  of  a 
prosobranch  having  a  canaliculated 
shell.  The  canal  exists  for  the  pur- 

FIG.  157.  —  Shell  of  Ful-  £  ,    .    .  , ,  .    , 

f/ur  (Sycotypus)  cam-    Pose    oi    containing    the    siphon    by 
culatus,  one    of  the    which  water  is  brought  to  the  animal 

Fasiolaridse.  One-  .  .  ? 

fourth  nat.  size.  Photo.    &$  it  lies  buried  in  the  sand.     Inilgur 
by  w.  H.  c.  P.  js  our  largest  common  gastropod.     Its 


Rough,  rude. 


2  A  cloak. 


Lightning. 


THE  SLUG   AND  ITS  ALLIES 


169 


shell  is  about  150  millimetres  long,  and  pear-shaped.      In 

one  species  the  margins  of  the  whorls  are  grooved  (Fig. 

157)  ;  in  the  other  they  are  carried  out 

into    thorns.      The    egg-cases  are  tough 

and  membranaceous  and    resemble  rows 

of    coin  strung  on    a  string,  the  whole 

being  slightly  coiled. 

In  Urosalpinx  :  the  canal  is  short  (Fig. 
158).  This  typical  representative  of  the 
Muricidae  is  everywhere  abundant  on  our 
Eastern  coast.  It  is  much  hated  by 
oystermen,  by  whom  it  is  known  as  the 
"  oyster  drill."  It  bores  through  the 
shell  of  this  and  other  bivalves  by  means 
of  its  radula  and  sucks  out  the  contents 
through  the  hole. 

Crepidula,2    the  boat   shell   or    "  decker,"    represents   a 
type  in  which  the  spire  has  become  almost  obsolete.     It  is 


FIG.  158.  —  Urosal- 
pinx, the  oyster 
drill.  Nat.  size. 
Photo,  by  W.  H. 
C.  P. 


FIG.  159.  — Crepidula,  the  boat  shell.     Two-thirds  nat.  size.    Photo,  by 
W.  H.  C.  P. 

still  represented,  however,  in  a  rudimentary  way  at  the  left 
of  the  aperture  (Fig.  159).  The  modified  shape  is  associated 
with  the  habit  the  mollusk  has  of  lying,  aperture  down- 

1  otpd,  tail ;  <rd\Triy£,  a  trumpet.  2  A  small  sandal  (crepida). 


170 


ZOOLOGY 


ve 


sh 


ward,  close  to  the  rock  or  another  shell.  By  this  means 
the  animal  is  better  protected.  The  "deck"  is  a  plate 

which  has  been  de- 
veloped internally  to 
help  hold  the  animal 
in  the  shell. 

The  limpets  are 
modified  prosobranchs. 
They  are  bilaterally 
symmetrical,  and  are 
covered  by  a  flat,  coni- 
cal shell,  which  is  ap- 
plied closely  to  the  rock 
all  around  the  base  in 
such  a  way  as  to  pro- 
tect the  animal  within. 
In  some  species  (genus 

FIG.   160.  —  Patella  vulgata,  seen   from  the    „.  „     1x     ,  . 

ventral  side.    /,  foot';  c/.i,  circlet  of  gill    *  issurella *)  there  is  an 

lamellae;  m.e,  edge  of  the  mantle;  mu,  at-  Opening  at  the  apex  of 

tachment  muscle;  si,  slits  in  the  attachment  *            °                             . 

muscle;    sh,    shell;    v,    efferent    branchial  the  shell  through  which 

vessel;*'  aorta  -,ve,  smaller  vessels.    From  the    water    ig    expelled 
the     Cambridge  Natural  History. 

which  has  passed  over 

the  gills.  Our  common  Eastern  rock  limpet  is  not  per- 
forated; it  is  known  as  Acmcea.2  In  Europe,  limpets 
(Patella,  Fig.  160)  are  used  as  food  ;  but  on  our  Eastern 
coast  they  are  too  rare  for  this. 

The  opisthobranch  mollusks  include  a  large  proportion  of 
symmetrical  shell-less  species.  The  most  familiar  of  these 
are  the  nudibranchs.  They  may  be  found  among  hydroids 
hanging  from  rocks,  or  in  tide-pools.  Our  species  are 
usually  less  than  20  millimetres  long.  They  are  often 


little  slit  or  fissure, 


,  in  full  bloom,  maturity. 


THE  SLUG  AND  ITS  ALLIES  171 

covered  with  numerous  gills,  which  give  them  a  velvety 
aspect.  When  placed  in  an  aquarium,  they  lay  eggs  in 
gelatinous  coils  on  the  hydroid  stems.  Eolis  l  is  a  com- 
mon genus  (Fig.  161). 

Besides  the  gastropods,  two  groups  of  mollusks  may  be 
briefly  mentioned  here.  In  one  group  the  body  is  very 

symmetrical,  not  only 

externally,    but    also 

internally,    which    is 

not     true     of     most 

symmetrical     gastro-    FIG.   m.  — chiton 

FIG.    Nil. —Eolis    (Cra-  j  A       oommon  (Trachydermon) 

tina),    a    nudibranch.  P018'  apiculatus,  the  ar- 

Nat.   size.     Photo,  of  representative  IS  Chi-  madillo  snail.  Nat. 

HvingNiimalbyW.H.  ^2(Fig.  162).    This  ^zeR  cP£oto'    ^ 

animal  has  a  sort  of 

coat  of  .mail,  since  its  shell  is  made  up  of  eight  pieces, 
lying  one  behind  the  other,  along  its  back.  When  removed 
from  the  rock  or  shell  on  which  it  rests,  it  coils  up  like  a 
pill-bug  or  armadillo. 

Coordinate  with  the  Gastropoda  is  the  group  of  Cepha- 
lopoda.3 In  this  group  belong  the  squids  and  cuttlefishes. 
They  have  a  large,  distinct  head,  a  circle  of  arms  about  the 
mouth,  a  funnel-shaped  foot,  and  huge  eyes  on  each  side  of 
the  head  (Fig.  163).  The  squids  are  the  best-known  cephal- 
opods,  since  they  travel  in  schools  in  our  harbors  and  are 
often  cast  upon  the  shore  after  a  storm.  They  can  also  be 
obtained  in  the  markets  of  our  coastwise  cities,  since  their 
flesh  is  used  to  a  certain  extent  as  food.  Cuttlefishes, 

1  Eolis,  daughter  of  Eolus,  the  god  of  the  winds. 

2  XIT^V,  coat,  case,  covering. 

3  Ke0aX^,  head  ;  TTOI/S,  foot ;  because  the  arms  or  foot  are  placed  around 
the  mouth, 


172 


ZOOLOGY 


best  known  from  their  "bones"  or  rudimentary  shells 
embedded  in  the  mantle,  are  inhabitants  of  deeper 
waters.  They  have  shorter  bodies 
than  the  squids,  and  their  arms  are 
eight  in  number  instead  of  ten 
as  in  the  case  of  the  squids.  In  both 
groups  locomotion  is  effected  by  the 
reaction  to  a  stream  of  water. which 
is  taken  into  the  mantle  chamber 
at  the  edges  of  the  mantle  and 
is  forced  out  through  the  "funnel," 
which  lies  between  the  eyes  in  Fig. 
163. 

The  shell  is  rudimentary  in  both 
the  squids  and  the  cuttlefishes,  and 
like  that  of  the  slug  is  embedded  in 
the  mantle.  Even  in  Spirula  the 
shell,  though  coiled  and  containing  a 
siphon,  is  completely  covered  by  the 
skin  of  the  animal.  There  are  two  liv- 
ing genera  of  Cephalopoda  which  have 
an  external  shell.  One  is  an  ally  of 
FIG.  K53.  —  LoU<jo  Peaiu,  the  cuttlefishes  —  the  paper  nautilus 

eastern  squid.  One-third  A  L     i       i  •    i      •      r  i    •         n 

nat.3ize  From  Rathbun.  or  Argonauta,1  which  is  found  in  all 
tropical  seas.     The  other  is  the  sole 

survivor  of  a  once  abundant  group.  This  is  the  Pearly 
Nautilus  of  the  Indian  and  Pacific  oceans.  Its  shell  is  di- 
vided into  water-tight  compartments,  in  the  last  formed 
of  which  the  animal  lies.  It  keeps  its  attachment  to 
the  shell  by  means  of  a  central  strand  of  tissue  —  the 
siphon  (Fig.  164,  «).  Allied  to  the  Nautilus  is  the  huge 

a  sailor  in  the  Aro. 


THE   SLUG   AND   ITS   ALLIES 


173 


family  of  Ammonites,  of  which  two  thousand  species  are 
known,  ranging  from  the  Silurian  up  to  the  Cretaceous 
formations. 


FIG.  164.  —  Nautilus  pompilius,  the  Pearly  Nautilus.  Median  section,  c,  outer- 
most chamber  whose  bottom  is  formed  by  the  septum,  se ;  s,  siphon  travers- 
ing all  compartments ;  e,eye;  h,  hood;  in,  part  of  mantle,  reflected  over 
the  shell;  I,  lobes  enclosing  tentacles  (<) ;  si,  incomplete  funnel;  im^  shell 
muscle ;  n,  gland  secreting  the  capsules  for  eggs.  After  Owen. 


174 


ZOOLOGY 


APPENDIX   TO   CHAPTER   XI 


KEY  TO  THE  PRINCIPAL  FAMILIES  OF  MARINE-SHELLED 
GASTROPODS  OF  THE  ATLANTIC  COAST  OF  THE  UXITED 
STATES,  ADAPTED  FROM  A.  C.  APGAR 

ai.    Shell  spiral,  of  one  to  many  whorls. 

61.  Spire  in  a  single  plane,  and  whorls  not  in  con- 
tact. [A  cephalopod  shell ;  liable  to  be 
mistaken  for  a  gastropod-shell,  page  172]  Spirit  I  idee 

62-    Spire  dextral. 

Ci.    Operculated  ;  aperture  not  over  \  area  of 

shell. 

d\.    Anterior  margin  of  aperture  entire. 
e\.   Shell    tubular ;  spiral    at  apex, 
irregularly  twisted  near  aper- 
ture        .        .        .        .        •  Vermetidce 
C2.    Shell  regularly  spiral,  elongated  ; 
width    less    than    £    length  ; 
whorls  5   or  more ;   angle   of 
spire  less  than  45°  ;   aperture 
less  than  \  length  of  shell, 
/i.   Whorls  rounded ,  almost  sepa- 
rated, crossed  by  elevated 
longitudinal  ribs  ;  aperture 
oval ;  lip  continuous  ;  our 
species  over  10  mm.  long  .  Scalariidce 
/2.    Whorls  about  5;  minute  shell, 
less  than  5  mm.  long ;  width 
about  i  length;   aperture 
about  J  length  ;  apex  blunt  Eissoidce 
/3.    Whorls    5-10 ;    shells    elon- 
gated,   conical,    turreted  ; 
aperture    £-$ ;    length    of 
shell  of  our  species  4-10 
mm.  long  ....      PyramideUidce 
es.   Shell  regularly  spiral,  shortened  ; 
width   nearly  as  great  as   or 
greater  than  length ;    whorls 


APPENDIX  TO   CHAPTER  XI 


175 


usually  few  ;  angle  of  spire 
always  over  50°,  usually  over 
90°  ;  aperture  over  \  length  of 
shell. 

.  Shell  conical,  pearly  under 
epidermis  and  within  aper- 
ture, usually  brilliantly  so  ; 
umbilicus  deep  and  large  . 
.  Shell  globular  or  oval  ;  spire 
short,  body  whorl  large  ; 
umbilicus  rounded,  dis- 
tinct, either  free  or  covered 
by  a  callus  ;  angle  of  spire 
90°  or  more 


/3. 


/4. 


Shell  top-shaped  to  globular  ; 
interior  pearly,  8-30  mm. 
long  ;  umbilicus  when  pres- 
ent not  rounded  nor  cov- 
ered with  a  callus  . 


Shell    minute,   nearly    disk- 
shaped,  widely  umbilicated 
Anterior  margin  of  aperture  notched 

or  produced  into  a  canal. 
a.   Shell  with  canal  formed  by  a  de- 
cided prolongation  of  anterior 
end. 

/i.  Large,  heavy  shells,  over  100 
mm.  long,  pear-shaped  ; 
whorls  angulated  or  nodu- 
lous .  .  .  . 

/2.  Rather  thin  shells,  20-80  mm. 
long,  ovate  to  pear-shaped  ; 
whorls  rounded  and  cov- 
ered with  40-60  small  re- 
volving ridges  .  .  . 

/s.  Shells  over  20  mm.  long,  with 
longitudinal,  rib-like  undu- 
lations crossed  by  revolving 
lines  . 


Trochidw 


Naticidce 

(Ex.  Natica) 


Littorinidce 

(Ex.  Littorina) 

Adeorbidce 


Fasciolariidce 

(Ex.  Fulgur) 


Biiccinidce 


Muricidce 

(Ex.  Urosalpinx) 


176 


ZOOLOGY 


/4.  Shells  less  than  20  mm.  long  ; 
aperture  with  a  notch  near 
posterior  end,  formed  by 
outer  lip  not  squarely  meet- 
ing body  wall  .  .  .  Pleurotomidce 
/s.  Shells  less  than  15  mm.  long ; 
aperture  entire  at  posterior 
end  ;  narrow,  and  a  little 
less  than  \  the  length  of 
the  shell ;  canal  rather 
short  ....  ColumbellidcR 
e».  Canal  short  or  absent ;  aperture 

notched, 
/i.    Shells  large,  40  mm.  or  more 

long ;  whorls  rounded        .  Buccinidw 

/2.    Shells     20-40     mm.     long; 

whorls  rounded         .         .  Muricidce 

/s.  Whorls  flattened,  surface 
usually  beaded ;  aperture 
over  i  length  of  shell  ,  Nassidw 

Non-operculated,  or  operculum  very  mi- 
nute ;   aperture  with   neither  a  canal 
nor  a  notch  at  anterior  end. 
d\.    Aperture  over  f  area  and  |  length  of 
shell ;  spire  distinct,  pointed  ;  shell 
ear-shaped     .       ,.        .        .        .  Naticitlf.e 

do.    Aperture  \  the  area  or  more,  and  the 

full  length  of  the  shell. 
e\.   Shell  with  1  whorl,  less  than  2 

mm.  long         .        .        ...  Philinidce 

€2-    Shell  with  several  whorls,  under 

4mm.  long;  spire  flat    ,:       .       Scaphandridas 
63.    Several  whorls,  a  pit  in  place  of 

spire,  over  6  mm.  long    .        .  Bull  idee 

ds.    Aperture  less  than  i  the  area  of  the 

shell. 

e\.  Aperture  f  to  whole  length  of 
shell ;  spire  distinct,  usually 
flattened  ;  under  lip  with  single 
fold  or  smooth  Tornatinidw 


APPENDIX   TO   CHAPTER   XI 


177 


e.2.    Aperture    i-f   length    of    shell  ; 
under  lip  with  2  or  more  teeth 

C3.    Non-operculated  ;  aperture  with  canal  at 
anterior  end ;   our  species  20  mm.  or 
less  long        .         .         .  x     .    •    . 
63.    Sinistral;  whorls  in  contact. 

d.    Shell  ovate-globose,  small,  not  over  5  mm. 
long,  transparent .        .        .        ... 

c2.    Shell    elongated,    turreted,  slender,  less 

than  30  mm.  long.         . 

c3.    Shell  large,  over  100  mm.  long,  with  pro- 
duced anterior  canal     .         .        . 
Shell  flat,  boat  or  cup  shaped,  if  somewhat  spiral, 

not  forming  a  complete  whorl. 
61.    Shell  with  apex  somewhat  spiral  and  an  in- 
ternal, usually  horizontal,  partition  or  dia- 
phragm      .       .'..;       .        ;        . 

62'    Shell  conical  or  cup-shaped,  with  apex  turned 

forward  ;  no  shelf  or  partition, 
d.   No  perforation  at  apex  or  notch  in  mar- 
gin       ..        .        ....        . 

c-2.    Apex  recurved ;   margin  or  apex  perfo- 
rated 


Auriculidce 

(Ex.  Melampus) 


Pleurotomidce 

Limacinidce 

Triforidce 

Fasciolariidw 


Calyptrwidce 
(Ex.  Crepidula) 


Acmceidce 

(Limpets) 

Fissurellidce 


CHAPTER  XII 

THE   FRESH-WATER   CLAM  AND  ITS  ALLIES 

THE  fresh-water  clams  belong  to  the  group  of  lamelli- 
branch  mollusks,  characterized  by  the  absence  of  a  distinct 
head,  by  the  possession  of  leaf-like  gills  on  the  sides  of  the 
body,  and  by  the  presence  of  a  calcareous  shell  composed 
of  a  right  and  a  left  valve.  Economically  this  group  is  the 
most  important  to  man  of  all  Mollusca.  It  includes  both 
marine  and  fresh-water  species.  About  six  thousand 
species  of  living  lamellibranchs  and  over  ten  thousand 
fossil  species  are  recognized.  They  all  fall  into  two  prin- 
cipal subdivisions.  The  first  (Siphonata)  includes  species 
which  possess  a  siphon  and  have  the  mantle  edges  grown 
together,  while  the  second  (Asiphonata)  has  no  siphon  and 
has  the  mantle  lobes  for  the  most  part  wholly  separated.1 

Anodonta  and  Unio  are  extremely  common  in  the  ponds, 
lakes,  and  rivers  of  North  America.  Anodonta  is  more 
apt  to  be  found  in  still  waters  and  Unio  in  running 
waters.  They  lie  partly  buried  in  the  mud  of  the  bottom, 
with  the  valves  of  the  shell  gaping  open  and  the  partly 
united  edges  of  the  mantle  protruding.  They  do  not  lead 
wholly  sedentary  lives,  but  may  burrow  or  plough  along 
the  bottom. 

Their  food  is  gained  from  organic  particles  borne  along 

1  A  key  to  the  principal  families  of  bivalve  shells  will  be  found  in  the 
Appendix,  p.  188. 

178 


THE  FRESH-WATER   CLAM  AND  ITS  ALLIES      179 

in  the  current  of  the  water.  A  part  of  this  current  is 
carried  through  the  mantle  chamber  and  forced  out  again, 
deprived  of  usable  food  and  of  the  oxygen  used  in  respira- 
tion. By  devouring  organic  matter  these  clams  act  as 
useful  scavengers  of  the  water. 

The  family  of  Unionidae,  to  which  Unio  and  Anodontia 
belong,  is  of  world-wide  distribution,  but  nowhere  else  are 
Unionidse  so  numerous  as  in  the  United  States.  They 
show  in  our  country  a  most  marvellous  variability  also,  so 
that  hundreds  of  kinds  have  been  described  from  our  waters. 
The  extraordinary  abundance  of  Unios  in  North  America 
is  due  to  the  fact  that  nowhere  else  is  there  such  a  large 
area  of  soluble  limestone  as  in  our  Mississippi  valley.  The 
clams  take  from  the  water  the  lime  which  they  use  in  the 
construction  of  their  shells,  change  it  into  an  insoluble 
form,  and  thereby  advantageously  reduce  the  amount  of 
the  inorganic  matter  in  solution,  for  this  change  in  the 
quality  of  the  water  renders  it  more  fit  to  drink  and  to 
sustain  other  animal  and  plant  life. 

Although  numerous  and  of  large  size,  the  Unionidse  do 
not  seem  to  be  much  used  as  human  food.  The  aborigines, 
however,  made  use  of  them,  as  the  great  shell-heaps  on  the 
banks  of  rivers  of  the  Ohio  valley  testify.  They  yield 
also  pearls,  which  occasionally,  especially  in  the  Ohio 
valley,  are  of  precious  quality.  Even  the  small,  imperfect 
pearls  are  of  value,  since  they  are  ground  up  to  make  the 
powder  used  in  polishing  the  more  valuable  pearls. 

The  spawning  season  of  our  Unionidse  is  short.  The 
eggs  pass,  during  the  latter  part  of  October,  into  the  gills 
of  the  parent,  where  they  undergo  their  early  development, 
protected  by  the  parent  shell  and  supplied  richly  with 
oxygen.  The  cleavage  is  unequal  because  of  the  larger 


180 


ZOOLOGY 


amount  of  yolk  in  some  of  the  cells  than  in  the  others. 
Eventually  a  shell  is  formed,  which  divides  into  two  valves 
united  by  a  straight  hinge.  A  spine  is  formed  on  the  free 
edge  of  each  valve,  and  a  thread  (byssus  thread)  is  secreted 
from  the  body.  The  young  at  this  stage  is  known  as 
Glochidium  (Fig.  165).  In  the  spring  Glochidia  become 
free  from  the  mother,  and  attach  themselves  to  the  gills  or 
fins  of  a  fish  by  means  of  the  spines  on  the  shells.  Here 
they  become  transformed.  The  single  adductor  muscle  dis- 
appears, and  becomes  replaced  by  the  two  characteristic  of 

"'  R. 


so.. 


B. 


FIG.  1H5.  —  A,  advanced  embryo  of  Anodonta;  B,  free  glochidium.  /,  pro- 
visional byssus ;  s,  shell ;  sh,  hooks ;  sin,  adductor  muscle ;  so,  sense  organs ; 
10,  cilia.  From  Korschelt  and  Heider's  "  Embryology." 

the  adult;  the  gills  arise,  the  shell  gains  its  adult  char- 
acter, and  becomes  free  from  the  fish  on  which  it  has  lived 
temporarily  as  a  parasite. 

There  are  other  species  of  fresh-water  lamellibranchs 
besides  the  Unionidae.  These  belong  to  the  Cycladidae, 
allies  of  the  marine  Cardidse  or  Veneridse.  They  have 
much  the  shape  of  our  common  hard-shell  clam  of  the  sea, 
but  are  much  smaller  in  size,  rarely  exceeding  15  milli- 
metres. Cyclas  (or  Sphserium)  is  of  world-wide  distribu- 


THE  FRESH-WATER   CLAM  AND  ITS  ALLIES      181 


tion,  but  it  is  especially  abundant  in  North  America, 
occurs  in  ditches,  ponds,  and  rivers 
of  New  England,  as  well  as  in  the 
South  and  West.  Some  species  of 
it  inhabit  brackish  water.  Pisidium 
has  both  valves  unsymmetrical.  Its 
species  are  still  smaller  than  those 
of  Cyclas,  rarely  exceeding  10  milli- 
metres. It  likewise  is  found  in 
ditches,  ponds,  and  streams  all  over 
our  country. 

The  remaining  families  which 
we  shall  consider  come  from  the 
sea,  and  all  occur  on  our  Eastern 
coast. 

The  Pholadidae1  and  Teredidae2 
include  certain  wood  arid  rock- 
boring  species,  which  do  great 
damage  by  boring  into  wooden 
vessels  and  pilings  (Fig.  166).  In 
such  locations  they  are  commonly 
called  ship-worms.  The  boring  is 
done  by  the  movements  of  the 
shell,  combined  with  the  action 
of  the  muscles  and  foot.  The 
only  thing  which  seems  effectively 
to  stop  these  mollusks  from  boring 
into  wood  is  iron  rust ,  so  that  piles 
driven  full  of  nails  are  apt  not  to 
be  attacked. 


It 


,  Greek  name  for  a  boring  mussel, 
to  bore. 


FIG.  1(56. —  Teredo  nayaHs, 
in  a  piece  of  timber.  P, 
pallets;  SS,  siphons;  T, 
tube;  V,  valves  of  shell. 
From  the  "Cambridge 
Natural  History." 


182  ZOOLOGY 

The  Solenidse1  include  the  "razor-shell"  (Fig.  167). 
This  animal,  like  the  shell,  is  elongated  and  subcylindrical. 
By  means  of  its  foot,  which  can  be  protruded  between  the 


FIG.  1G7.  —  Enxis  directus.    Young.    Nat.  size.    Photo,  by  W.  H.  C.  P. 

\alves,  it  excavates,  with  great  rapidity,  a  hole  in  the  sand 
or  mud,  into  which  it  draws  itself.  These  mollusks  are 
sometimes  used  for  food,  but  it  is  not  easy  to  get  them  in 
quantity. 

The  Mactridae  2  include  species  commonly  known  in  the 
North  as  hen-clams  and  surf-clams.  They  are  more  ellip- 
tical and  larger  than  the  common  hard-shelled  clam  or  "  quo- 
hog,"  and  have  a  proportionately  lighter  shell  (Fig.  168). 
They  are  not  often  used  as  food  because  they  become  very 
tough  when  cooked. 

The  Myidae 3  include  the  common  clam  of  New  England, 
My  a  arenaria,  abundant  along  our  whole  Eastern  coast  and 
used  as  food  chiefly  in  New  England.  These  clams  occur 
in  great  numbers  in  every  mud-flat.  Their  great  siphon  is 
extended  at  high  tide  to*  the  surface  of  the  ground,  so  as  to 
take  in  and  throw  out  water  (Fig.  169)  ;  but  at  low  tide  it  is 
retracted,  and  the  clam  lies  invisible  in  its  burrow.  This 
clam  was  much  prized  by  the  Indians,  as  the  great,  ancient 
shell-heaps  along  the  coast  testify.  In  1892  the  clam  com- 

,  a  channel  or  tube.  2  ndicrpa,  a  baking-trough. 

3  /AiJa,  Greek  name  for  a  kind  of  mussel. 


THE  FRESH-WATER   CLAM  AND  ITS  'ALLIES      183 

merce  for  New  England  was  estimated  to  be  worth  nearly 
half  a  million  dollars, 


FIG.  168.  — Mactra  solidissinia,  the  Eastern  hen  clam.     Nat.  size.    From 
Gould-Binney. 

The  Veneridae :  include  the  hard-shelled  clam  or  "  quo- 
hog  "  of  the  Indians.  Venus  mercenaries  is  the  commonest 
species,  and  is  most  abundant  south  of  Cape  Cod.  It  owes 


FIG.  169.  —  Mya  arenaria,  the  New  England  "  clam."  At  the  left  the  foot  is 
seen  ;  at  the  right,  the  siphon.  One-half  nat.  size.  From  Verrill,  "  Inverte- 
brates of  Vineyard  Sound." 

1  Venus,  the  goddess  of  love. 


184 


ZOOLOGY 


its  name  "  mercenaria  "  to  the  fact  that  the  purple-colored 
patch  seen  on  the  margin  of  the  shell  was  used  as  money 


FIG.  170.  —  Venus  mercenaria,  the  hard-shelled  clam.  At  the  left  the  foot 
protrudes  from  the  shell ;  at  the  right  the  siphons.  Nat.  size.  From  Verrill, 
"  Invertebrates  of  Vineyard  Sound." 

("  wampum  ")  by  the  Indians.    The  shell  is  extremely  heavy, 
and  usually  nearly  circular  in  outline  (Fig.  170). 

The  Arcidae *  and  their  allies  include  several  species  hav- 
ing a  more  or  less  elongated 
hinge -joint  crowded  with 
many  small  teeth.  Our  com- 
mon Eastern  species  (Area 
pexata,  Fig.  171)  has  bright 
red  blood  and  is  commonly 
known  as  the  "bloody  clam." 
The  Mytilidae  2  include 

FIG.  171.  —  Area  pexata,  the  bloody  J 

clam.     Nat.   size.      Photo,   by     the    mussels,   which   are    the 

W.  H.  C.  P. 


1  area,  an  ark. 


2  /iUTi'Xos,  an  edible  mussel  of  the  Greeks. 


THE  FRESH-WATER    CLAM  AND  ITS  ALLIES      185 

familiar  blue-black,  wedge-shaped  shells  attached  in  clus- 
ters or  beds  to  rocks  near  low  tide  (Fig.  172).  They  are 
edible.  In  France  they  are  reared  for  the  market  on 
woven  nets,  which  are  submerged  at  each  tide. 


FIG.  172.  —  A  bed  of  Modiola,  the  horse-mussel,  on  a  mud-bank.     Photo,  by 

W.  H.  C.  P. 

The  Aviculidae l  are  a  group  closely  allied  to  the  last,  but 
not  represented  on  our  shores.  It  is  important  because 
mollusks  of  this  family  produce  the  best  pearls.  Pearl- 
fishing  has  been  carried  on  since  the  earliest  preserved 
historic  records.  The  pearl  banks  of  Ceylon  are  known 
1  A  small  bird  (avis). 


186 


ZOOLOGY 


to  have  been  fished  for  two  thousand  years.  The  finest 
pearls  come  from  the  Persian  Gulf.  They  are  gathered 
there  by  native  divers,  who,  after  taking  several  deep 
inspirations,  either  dive  down  unaided  or  descend  upon 
weighted  ropes.  When  they  can  no  longer  remain  under 
water,  they  either  ascend  again  unaided  or  are  rapidly 
drawn  up  to  the  boats  above.  The  pearl  oysters  brought 
up  to  the  surface  are  then  examined  for  pearls.  The  pearl 
is  the  secretion  of  the  oyster  about  a  small  foreign  body, 

such  as  a  grain  of  sand. 
This  secretion  prevents  the 
irritant  from  injuring  the 
tissues.  It  is  of  the  same 
nature  as  the  substance  lin- 
ing the  shell.  The  latter 
is  the  mother  of  pearl  of 
commerce,  and  is  used  for 
knife  handles,  buttons,  and 
the  like.  The  iridescence 
is  not  due  to  the  chemical 
composition  of  the  secreted 
substance,  but  to/  the  fact 
that  it  is  deposited  so  as  to  leave  fine  lines  on  the  surface 
which  diffract  the  light. 

The  Pectinidae 1  include  the  scallop-shells.  These  occur 
along  our  whole  coast.  They  live  in  shallow  water,  and 
are  capable  of  rapid  movement  in  the  water  by  clapping 
the  valves.  The  adductor  muscle  of  the  valves  alone  is 
eaten  by  man.  The  common  species  is  Pecten  irradians. 
It  varies  greatly  in  color,  from  bluish  to  reddish  and 
orange  (Fig.  173). 

1  pecten,  comb. 


FIG.  173.  — Pecten  irradians,  scallop, 
left  or  upper  valve.  Nat.  size. 
Photo,  by  W.  H.  C.  P. 


THE  FRESH-WATER   CLAM  AND  ITS  ALLIES      187 


The  Ledidae  include  certain  elongated  shells  with  a 
shiny  epidermis,  and  a  large  number  of  teeth  on  the  hinge, 
which  are  found  chiefly  in  mud  in  rather  deep  water. 
The  animal  has  a  large  foot 
(Fig.  174)  with  which  it  bur- 
rows rapidly.  It  can  also 
move  rapidly  through  the 
water  as  the  scallops  do. 

The  Ostreidae1  include  the 
oysters,  which  are  the  most 
important  invertebrate  food 
fishery,  being  valued  at 
twenty  to  thirty  million  dollars  per  year  for  our  Atlantic 
seaboard.  Oysters  are  found  on  all  coasts.  Our  Ostrea  vir- 
giniana2  extends  from  the  Gulf  of  St.  Lawrence  to  the  Gulf 
of  Mexico.  The  oysters  of  our  Western  coast  are  not  so 
important  as  the  Atlantic  species.  0.  edulis  is  the  prin- 


FIG.  174.  — Yoldia,  one  of  the  Lc- 
didae.  Foot  protruding  below. 
Nat .  size.  Photo .  by  W .  H.  C .  P . 


FIG.  175.  —  Ostrea  virgmiana,  the  Eastern  oyster.    One-third  iiat.  size. 
Photo,  by  W.  H.  C.  P. 

cipal  European  species.  In  Japan  there  is  a  species  occa- 
sionally gaining  a  length  of  three  feet.  The  oyster 
was  formerly  commoner  and  larger  north  of  Cape  Cod  than 

1  From  Greek  name  for  oyster.  2  Eig.  175. 


188 


ZOOLOGY 


it  is  now,  for  the  great  aboriginal  shell-heaps  ("  Kitchen- 
middens  ")  of  the  New  England  coast  contain  shells  of 
enormous  size.  The  cause  of  this  gradual  extinction  of 
the  oyster  is  uncertain,  but  is  believed  to  be  due  partly  to 
general  climatic  and  geographic  changes  and  partly  to 
over-fishing, 

APPENDIX   TO    CHAPTER   XII 


KEY    TO    THE     PRINCIPAL     FAMILIES    OF    MARINE    LAMELLIBRAN- 
CHIATA    OF    THE    EAST    COAST    OF    THE    UNITED    STATES 

ADAPTED  FROM  A.   C.   APGAR 

a\.     Shell  when  closed  at  ventral  side,  gaping  more  or 

less  at  the  ends. 

61.  Without  toothed  hinge  or  proper  ligament, 
often  with  accessory  valves  ;  no  distinct  epi- 
dermis. 

t'i.     Length  decidedly  greater  than  height 
C2.     Length   and   height   nearly  equal ;   shell 
small    .         ... 

&:>.     With  proper  hinge,  often   distinctly  toothed 

and  with  hinge  ligament  or  pad. 
Ci.     Hinge  with  many  small  cardinal  teeth  in 
each  valve    .         „        ... 

Co.     Hinge  of   not  over  4  cardinal   teeth   in 

each  valve. 
di.     Shells  equivalve. 

e\.  Two  or  more  times  as  long  as 
high,  gaping  more  or  less  at 
ends. 

/i.     Length  3  to  6  times  height ; 
epidermis  polished  ;  um- 
bones  not  over  one-quar- 
ter from  anterior  end     .  Solenidce 
(Kazor  Clams) 


Pholadidw 
Teredidcv 

(Shipworms) 


Ledidw 
(Ex.  Yoldia) 


APPENDIX   TO   CHAPTER  XII 


189 


/2.     Length     about     3    times 

height ;  umbones  central,   Psammobiidce 
/3.     Length  less   than  3  times 

height ;  surface  covered 

with  radial  ridges,  chalky 

white,  umbones  near  an- 
terior end       .         .         .        Petricolidce 
/4.     Length      about    2     times 

height;     epidermis 

polished,    with    notched 

border  extending  beyond 

the  edge  of  the  thin  shell,         Solemyidce 
/4.    Shell     with     thick    black 

epidermis ;  external  liga- 
ment prominent  and  on 

shorter  end  of  the  shell,        Saxicavidce 
Length  less  than  twice  height, 
/i.     Shell  somewhat  triangular, 

with    internal    cartilage 

between  deep  triangular 

pits,   similar  in    each 

valve 


f.2.     Shell  thin,rounded  in  front, 
narrowed  and  gaping  be- 
hind, cartilage  pit  shal- 
low;   external   ligament 
short      .        . 
Shells  inequivalve. 
e\.     Length  and  height  about  equal, 
e^     Length  decidedly  greater  than 

height. 

/i.  Over  25  mm.  long ;  right 
valve  nearly  flat ;  whole 
shell  compressed  to  one- 
sixth  length  .  .  . 
/2.  Over  50  mm.  long  ;  slightly 
inequivalve  ;  no  external 
ligament;  internal  car- 
tilage on  spoon-shaped 
process  of  left  valve 


Mactridce 
(Hen  Clams) 


Semelidw 


Pandoridce 


Myidw 


(Soft-shelled  Clftins) 


190 


ZOOLOGY 


/3.     Shell  under  18  mm.;  promi- 
nent external  ligament, 
«2.     Shell  not  at  all  gaping. 

b\.     With  not  over  3  cardinal  teeth  in  each  valve. 
ci.     Valves    equal    in    size,    curvature,    and 

markings. 

d\.  Anterior  muscular  impression  very 
small,  hinder  large;  shell  elongated, 
mussel-shaped  ;  umbo  at  or  near 
posterior  end  .... 

<?2.  Hinge  line  straight,  formed  by  ears 
at  sides  of  umbo,  radiating  ribs, 
scalloped  edge  .... 


Tellinidas 


MytUidcB 

(Mussels) 


Pectinidce 

(Scallops) 


Co. 


(73.     Height  and  length  nearly  equal  ;  a 

decided  pallial  sinus     .         .        .  Veneridce 

(Hard-shelled  Clams) 

d±.  Height  and  length  nearly  equal  ;  no 
distinct  pallial  sinus,  at  most  a 
mere  undulation  of  pallial  line  at 
posterior  end. 

e\.  With  a  plain  lunule  in  front  of 
umbones;  without  radial 
ribs. 

/i.     Over  20  mm.    long,   com- 
pressed, ligament  external          Astartidce 
/2.     Shell    somewhat   quadrant 
shaped ;  less  than  8  mm. 
long;   surface   with  con- 
centric ridges.         .         .    CrassateUidce 
/3.     Shell  less  than  5  mm.  long, 
very  much   compressed  ; 
ends  rounded .         .      '  jp;        Erycinidce 
e^     With  no  lunule  and  with  dis- 
tinct radial  ribs     .        .        .  Cardiidca 
Valves  unsymmetrical. 
d\.     2   muscular    impressions,  a  distinct 

pallial  sinus.     (See  d2  under  a\.) 
rf2.    1  muscular  impression  ;  height  never 
much  less  than  length 


APPENDIX   TO   CHAPTER  XII 


191 


ci.  Fixed  mollusks  with  large  rough 
shells  attached  by  large  valves, 

e2-  Fixed  mollusks,  with  their  pearly 
shells  attached  by  smaller 
valve  which  is  flat  or  concave 
and  perforated  or  notched 

e3.     Free     mollusks ;      hinge     line 

straight,   formed  by  ears  at 

sides  of  umbo ;   with   radial 

ribs        ..... 

With  many  small  cardinal  teeth  in  each  valve. 

d.     With  distinct  radiating  ribs  ;  shell  over 

30  mm.  long         ..... 

Cs-  Smooth,  length  and  height  equal ;  under 
12  mm.  long 

c3.  Elongated  shells,  length  nearly  or  twice 
height ;  a  pallial  sinus  .  .  .  •. 


Ostreidce 

(Oysters) 


Anomiidce 

(Jingle  shells) 


Pectinidce 

Arcidce 

(Ark-shells) 

Nuculidas 
Ledidce 


KEY    TO    THE    PRINCIPAL    GENERA    OF    FRESH-WATER    LAMELLI- 
BRANCHIATA 


a\.     Siphonate  ;  without  marked  muscular  impression, 


Fam.  Cycladidce 
.  Genus  Cyclas 
.  ,  Pisidium 
Fam.  Unionidce 


b\.  Valves  sub-symmetrical  .... 
62-  Valves  unsymruetrical ;  siphons  united  . 
Asiphonate  ;  with  two  muscular  impressions  . 
&i.  Hinge  with  teeth. 

Ci.     With  short  cardinal  teeth  and  long  lateral 

teeth     .        .  •»     .  __^  .^-   ,  •     -.        ,  Unio 

63.     With  short  cardinal  teeth  and  no  lateral 

teeth     .         .         .-       .        ...     Margaritann 
Hinge  without  teeth,  or  with  only  a  small  ridge,          Anodonta 


CHAPTER   XIII 
THE  STARFISH  AND  ITS  ALLIES 

Systematic  Position.  —  The  starfishes  belong  to  the 
group  of  Echinodermata,1  characterized  by  a  radial,  usually 
five-rayed,  structure,  a  more  or  less  well-developed  system 
of  calcareous  plates  in  the  skin  ;  a  system  of  water-tubes, 
which  is  used  by  the  movable  forms  for  locomotion;  and 
the  separation  of  the  intestine  from  the  body  cavity. 

Distribution  and  Habitat.  —  The  common  pink  starfish  of 
the  eastern  United  States  (Asterias2  vulgaris^)  ranges 
from  Labrador  to  northern  Florida.  A  dark  brown  form, 
sometimes  called  Asterias  Forbesii^  is  recognized  by  some 
authors  as  a  separate  species  inhabiting  the  coast  from 
Massachusetts  Bay  southward.  Our  shore  starfish  extends 
out  into  fairly  deep  water,  but  is  not  abundant  at  greater 
depths  than  60  fathoms.  In  Long  Island  Sound  it  is 
found  especially  on  the  oyster  beds,  where  it  is  very 
destructive.  On  rocky  coasts  starfishes  will  be  found  in 
crevices  of  the  rock  or  in  tide-pools.  They  love  cool 
waters,  and  are  often  found  hanging  on  vertical  walls  or 
ledges.  Upon  reaching  the  surface  of  quiet  water,  they 
may  extend  one  or  more  of  their  arms  out  upon  the  under 
side  of  the  surface  film. 


1  ^x*"°s?  hedgehog,   sea-urchin  ;    5fy/xa,  skin.     A  key  to  the  principal 
classes  of  Echinodermata  will  be  found  in  the  Appendix  to  this  Chapter. 
*  aer-tip,  star  ;  aarepias,  starred. 

3  Common.  4  Of  Forbes,  an  English  zoologist. 

192 


THE  STARFISH  AND  ITS  ALLIES  193 

Food.  —  The  favorite  food  of  the  starfish  is  some  kind  of 
mollusk,  especially  bivalves,  such  as  mussels  and  oysters. 
Their  method  of  feeding  is  as  follows:  They  crawl  over 
the  bivalve,  arch  the  body  over  it,  apparently  pull  open 
the  valves,  then  turn  the  stomach  inside  out  over  the  soft 
body  within  the  shell,  and  gradually  digest  it.  The  star- 
fish probably  finds  its  food  by  means  of  a  keen  chemical 
sense. 

Starfishes  are  of  economic  importance  on  account  of  their 
destructiveness  to  oysters,  but  since  the  oystermen  have 
learned  to  keep  the  beds  clear  of  starfishes  and  that  tear- 
ing starfishes  into  pieces  only  aids  in  their  increase,  as 
each  piece  produces  a  whole  starfish,  the  damage  wrought 
by  starfishes  must  be  less  than  it  was  formerly. 

Development.  —  Starfishes  have  the  sexes  distinct ;  and 
the  sex  can  usually  be  told  by  the  color.  The  female  has 
a  more  bluish  tint,  while  the  males  are  of  a  reddish  brown 
color.  Both  the  eggs  and  sperm  are  extruded  into  the 
water  through  small  openings  on  the  aboral  surface  at  the 
interspace  between  two  adjacent  arms.  The  egg  is  hardly 
visible  to  the  naked  eye,  and  is  enclosed  in  a  delicate 
membrane.  The  egg  undergoes  cleavage  ;  that  is  to  say, 
the  single  sphere  breaks  up  into  two,  four,  eight,  sixteen 
spheres,  and  so  on.  Finally  a  hollow  ball,  made  up  of 
these  spheres  or  cells,  is  formed,  called  the  "blastula." 
Next  the  wall  of  this  hollow  sphere  is  pushed  in  at  one 
side,  forming  a  sort  of  cup  with  two  walls.  This  is  the 
so-called  "gastrula."  The  cavity  of  this  cup  is  the 
digestive  cavity.  At  first  it  is  a  sac  with  only  one 
opening,  but  later  a  second  opening,  the  true  mouth, 
breaks  through,  and  the  former  opening  persists  as  the 
anus.  Pairs  of  arms,  edged  with  cilia,  now  bud  out  on 
o 


194  ZOOLOGY 

each  side  of  the  body,  and  the  larva  becomes  bilaterally 
symmetrical.1  Meanwhile,  inside  the  body,  the  system 
of  water  tubes  of  the  adult  starfish  has  begun  to  form, 
and  finally,  over  the  stomach  on  the  left  side,  five  main 
water  tubes,  radially  arranged,  make  their  appearance ; 
these  are  the  five  radial  tubes,  one  of  which  runs  down 
each  future  arm.2  On  the  right  side  of  the  stomach,  calca- 
reous plates  are  laid  down  to  form  the  aboral  wall  of  the 
starfish.3  The  young  star  is  now  found  as  a  parasite  at  the 
hinder  end  of  the  larva.  Soon  all  the  front  end  of  the  larva, 
together  with  the  long  arms,  becomes  absorbed.  Up  to 
this  stage  the  larva  has  been  free-swimming,  but  it  now 
settles  to  the  bottom.  There  the  process  of  resorption  is 
completed,  the  upper  and  lower  surfaces  of  the  star 
approach  each  other,  the  calcareous  skeleton  and  suckirig- 
feet  rapidly  develop.  At  this  stage  the  disk  is  so  large, 
and  the  arms  so  short,  that  the  young  starfish  looks  more 
like  a  sea-urchin  than  an  adult  starfish.  The  elongated 
arms  and  the  pedicellarise  of  the  adult  are  not  gained  until 
three  years  have  passed. 

1  Figs.  176  and  177.  2  Fig.  178.  Fig.  179,  ab'. 


FIG.  176-179.  —  Larval  stages  and  metamorphosis  of  starfish.  After  drawings 
of  E.  B.  Wilson,  from  Brooks,  "  Invertebrate  Zoology." 

FIG.  176.  —  Dorsal  view  of  starfish  larva  with  beginnings  of  ciliated  arms. 

FIG.  177.  — Ventral  view  of  same  larva. 

FIG.  178.  —  Side  view  of  an  older  larva  in  which  young  star  is  beginning  to 
arise.  , 

FIG.  179. — Ventral  view  of  same  larva,  a,  anterior  end;  b,  posterior  end; 
1-4,  ciliated  projections;  a',  preoral  arms;  am,  oral  surface  of  young  star 
with  beginning  water  tubes,  om-aw5;  ab,  ab',  afr5,  aboral  surface  of  star; 
c,  postoral  arm  ;  i,  intestine ;  in,  mouth ;  n,  lateral  arm ;  o,  anus ;  ce,  oesopha- 
gus; q,  g',  dorsal  lateral  arms;  s,  stomach;  ww',  water  tubes;  am,  Fig.  177. 
region  from  which  water  tubes  arise. 


FIG.  179. 


196 


ZOOLOGY 


Abnormalities  are  frequently  found  among  starfishes,  — 

partly  on  account  of  their 
capacity  for  regeneration, 
even  from  the  disk  and  a 
single  arm.  Thus  one  may 
find  a  starfish  with  three  or 
four  rays,  or  with  a  small 
ray  interpellated  in  be- 
tween normal-sized  ones. 
Not  all  abnormalities  seem 
to  be  the  result  of  mutila- 
tion, however;  for  example, 
sometimes  two  arms  seem 


FIG.  180. —Abnormal  starfish  (Asterias), 

apparently  produced  by  fusion  of  two    to  be  tused  (b  Ig.  18U). 
rays.     One-half  nat.  size.    Photo,  by 
W.  H.  C.  P. 


Other  Starfishes.  —  Aste- 


FIG.  181.  —  Cribrella  sanguinolenta.    Nat.  size.    From  Leunis. 


THE  STARFISH  AND  ITS  ALLIES 


197 


rias  vulgaris  belongs  to  the  group  Asteroidea.1  But  there  are 
over  five  hundred  other  species  of  starfishes.  In  some  of 
these  —  as  in  Asterias  —  the  skele- 
tal plates  of  the  skin  make  a  net- 
work ;  in  others  they 
form  a  solid  calcare- 
ous covering.  To  the 
first  class  belong,  besides 
Asterias  vulgaris,  Aste- 
rias ocliraceaf  which  oc- 
curs commonly  on  the 
Pacific  coast  from  Sitka, 
Alaska,  to  San  Diego, 
California.  This  has  a 
much  thicker,  more 

solid      skin      than      the     FIG.  182.  —  Solaster,  a  multirayed  starfish. 

Atlantic  species.    A.  gi- 

gantea*  attains  a  diam- 
eter of  over  two  feet. 
Next  to  A.  vulgaris, 
our  commonest  Eastern 
species  is  a  smooth, 
leathery,  blood-red  star- 
'6p£~\  fish,  about  10  centi- 
metres in  diameter, 
called  Cribrella  *  san- 


star  ;  e?5oj,  form. 
,  pale  yellow. 

3  yiganteus,  gigantic.     This 
species  occurs  on  our  Pacific 
FIG.  183.  —  Archiaster,  a  webbed  starfish.      coast. 
Slightly  reduced.    Photo,  by  W.H.C-P.  4  cribrum,  sieve, 


198  ZOOLOGY 

guinolenta1  (Fig.  181).  Certain  starfishes  have  many 
arms  instead  of  only  five,  as  in  the  case  of  Solaster  2  endeca  3 
of  the  northern  Atlantic  (Fig.  182).  In  still  other  star- 
fishes the  rays  are  partially  connected  by  a  membrane  like 
the  web  of  a  duck's  foot,  so  that  the  whole  outline  is 
nearly  pentagonal  (Fig.  183). 

The  Ophiuroidea.  —  In  the  Ophiuroidea 4  the  organs  are 
not  prolonged  from  the  disk  into  the  arms,  consequently 


FIG.  184. — Amphiura  squamata.    One  of  the  Ophiuridae.    Nat.  size. 
Photo,  by  W.  H.  C.  P. 

the  arms  may  be  thrown  off  without  injury  to  the  animal ; 
hence  the  name  "brittle-star."  The  brittle-stars  fall 
into  two  groups,  in  one  of  which,  the  serpent-stars,  the 
arms  are  unbranched,  while  in  the  other,  the  "basket- 
fish,"  the  arms  are  branched. 

Of  the  serpent-stars  there  are  two  common  forms  on  the 
New  England  coast,  —  a  white  species,  with  long,  slender 
arms,  Amphiura 5  squamata 6  (Fig.  184),  and  the  spotted 
Ophiopholis,7  which  has  shorter,  stouter  arms.  The 

1  Blood-red.  5  dfj.<f>l,  round  about ;  ofy><£,  tail. 

2  sol,  sun  ;  aster,  star.  6  Scaled  (squama,  a  scale). 
8  ^Se/ca,  eleven.                               7  00is,  snake  ;  0o\/s,  scale. 

4  00ts,  serpent ;  ovpd,  tail. 


THE  STARFISH  AND  ITS  ALLIES  199 

animals  live  in  crevices  of  the  rock,  and  being  of  rather 
small  size,  are  not  commonly  seen.  At  the  base  of  the  arms, 
on  the  right  and  left,  are  a  pair  of  slits,  which  form  the 
exits  from  pouches  into  which  the  reproductive  glands 
open.  In  certain  species  the  pouches  are  used  for  brood- 
ing the  young.  The  basket-fish  occur  in  Northeastern 


FIG.  185.  —  Strongylocentrotus,  the  Eastern  green  sea-urchin,  with  tube  feet 
extended.    From  "  Standard  Natural  History." 


waters,  from  low  tide  to  one  hundred  fathoms,  and  are 
often  brought  up  by  fishermen,  to  whose  lines  they  have  a 
habit  of  clinging.  The  branching  of  the  arms  enables  the 
animal  to  hold  its  prey,  which  consists  of  shrimp  and  fish. 
The  Echinoids,  or  sea-urchins,  may  be  regarded  as  star- 
fishes in  which  the  arms  have  shortened  and  the  disk  en- 
larged so  as  to  fill  up  the  interspaces,  and  make  a  solid, 


200 


ZOOLOGY 


nearly  spherical  form.  The  sea-urchins  eat  various  small 
animals,  and  get  food  also  from  small  bits  of  organic  matter 
in  the  mud  which  they  swallow.  They  live  more  concealed 
than  the  starfish,  for  some  burrow  in  the  mud  and  others 
—  such  as  our  green  sea-urchin  of  the  Maine  coast  (Fig. 
185) — grind  out  pockets  in  the  rocks  by  means  of  their 
spines.  Others  cover  themselves  with  seaweed,  and  thus 
become  inconspicuous.  Besides  the  green  sea-urchin, 


FIG.  186.  —  Arbacia,  the  Eastern  black  sea-urchin.    Tube  feet  retracted.    Nat. 
size.    Photo,  by  W.  H.  C.  P. 

which  is  found  north  of  Cape  Cod,  we  have  a  black  sea- 
urchin  (Arbacia,  Fig.  186),  which  extends  south  as  far  as 
North  Carolina.  We  have  on  the  east  coast  also  two  kinds 
of  flat  sea-urchins  (sand-dollars),  which  live  in  the  sand 
from  low  water  to  one  hundred  fathoms.  Their  spines 
are  small  and  silky  (Fig.  187).  Some  sea-urchins  lose 
their  strictly  radial  form  and  become  bilateral,  having  a 
pointed  anterior  end  (Fig.  188). 


THE   STARFISH  AND  ITS   ALLIES 


201 


The  Holothurians 1  may  be  likened  to  soft-skinned  sea- 
urchins,  with  the  body  drawn  out  to  the  form  of  a  cucum- 


FIG.  187.  —  Echinarachnius  paruia, 
the  sand  dollar.  Spines  removed 
from  left  side.  Nat.  size.  Photo, 
by  W.  H.  C.  P. 


FIG.  188.  —  Clypeaster,  a  bi- 
lateral sea-urchin  from  the 
West  Indies.  Spines  partially 
removed  and  surface  rubbed 
in  patches.  Reduced  photo. 


ber,  or  even  of  a  worm.  The  calcareous  skeleton  is  reduced 
to  small  plates  embedded  in  the  skin.  The  mouth  is  sur- 
rounded by  a  circle  of  tentacles. 
The  ambulacral  feet  are  sometimes 
absent.  The  Holothurians  live  in 
sand  and  mud,  often  deeply  buried, 
and  feed  on  small  marine  animals 
or  the  decaying  particles  mingled 
with  the  mud  which  they  devour. 
They  are  of  considerable  economic 
importance.  The  members  of  one  genus  (Holothuria)  is 
taken  in  great  numbers  on  the  coral  reefs  of  the  Pacific 

,  a  sort  of  water-polyp. 


FIG.  189.  —  Caudina,  the 
tailed  Holothurian.  a, 
mouth;  b,  anus.  After 
Selenka. 


ZOOLOGY 


FIG.      191.  —  Metacrinus      interruptus. 
After  P.  H.  Carpenter. 


FIG.  190.  —  Synapta  inhere  us.  a, 
tentacles;  b,  longitudinal  mus- 
cles; c,  alimentary  tract. — 
After  Quatrefages. 


Ocean  and  the  China 
Sea,  where  they  are  com- 
monly known  as  "  t re- 
pangs."  They  are  cut 
open,  washed,  boiled, 
dried,  and  sometimes 
smoked.  They  are  sold 
in  Chinese  ports,  and 
some  species  are  con- 
sidered by  Chinese  epi- 
cureans as  great  deli- 
cacies. Several  species  of 
Holothurians  occur  on 
the  Maine  coast.  A  bar- 
rel-shaped form  with  a 


APPENDIX  TO   CHAPTER  XIII  203 

sort  of  tail  (Caudina,1  Fig.  189)  occurs  on  the  Massa- 
chusetts coast.  A  worm-like  form,  but  with  a  beautifully 
transparent  skin  (Synapta,2  Fig.  190),  is  found  in  sandy 
beaches  from  Massachusetts  to  New  Jersey. 

The  Crinoids,3  or  sea-lilies,  are  familiar  as  fossils  to  resi- 
dents of  New  York  State  and  the  Ohio  and  Mississippi 
valleys.  The  living  animals  are  less  often  seen,  for  they 
are  inhabitants  of  the  deep  sea.  They  have  a  cup-like 
body,  with  the  mouth  at  its  centre  directed  upward,  and 
surrounded  by  tentacles  (Fig.  191).  The  cup  is  either 
borne  on  the  end  of  a  long  stalk  or  is  unstalked.  The 
former  condition  is  more  usual  among  the  fossil  species. 


APPENDIX   TO    CHAPTER   XIII 

KEY    TO    THE    PRINCIPAL    CLASSES    OF    ECHIXODERMATA 

a\.    Sessile  ;  mouth  turned  upward  ;  body  calyx-shaped  Crinoidea 

(Sea-lilies) 

a«.   Not  sessile. 

61.    Body  short ;  skin  hard,  containing  calcareous 
plates  ;  mouth  directed  downward  ;  madre- 
poric  plate  present. 

Ci.    Body  with  arms  which  carry  a  longitu- 
dinal series  of  plates. 
d\.    Arms  with  ventral  furrow  .         .         Asteroidea 

(Starfish) 

d%.    Arms  without  ventral  furrow      .         .       Ophiuroidea 

(Serpent  stars) 

1  cauda,  tail. 

2  <rvvaiTT6s,  fastened  together ;  from  o-i/v,  with,  and  ATTTW,  to  fasten. 

3  Kpivov,  lily  ;  e!5os,  form. 


204  ZOOLOGY 

c2.    Body  without  arms  ;  more  or  less  spheri- 
cal or  cake-shaped  ....        Echinoidea 

(Sea-urchins) 

52.  Body  elongated;  skin  soft,  leathery,  contain- 
ing microscopic  calcareous  bodies  ;  madre- 
poric  plate  absent ;  mouth  surrounded  by 
tentacles Holothuroidea 

(Sea-cucumbers) 


CHAPTER  XIV 

THE  HYDRA  AND   ITS   ALLIES 

HYDRA  belongs  to  the  group  of  Ccelenterata,1  which 
includes  sponges,  and  certain  organisms  with  nettling 
capsules  —  Cnidaria.2  The  Ccelenterata  have  a  more  or 
less  radial  form,  and  a  system  of  internal  cavities  serving 
for  digestion  as  well  as  for  body  cavity. 

The  sponges  are  all  sessile,  have  no  nettling  capsules, 
have  the  body  wall  perforated  by  many  fine  incurrent 
openings,  and  a  larger  exhalant  opening  (Fig.  192). 

The  Cnidaria3  have  nettling  organs  of  some  sort. 
Hydra  belongs  to  this  group. 

There  are  two  common  species  of  Hydra  ;  the  one  is  of 
a  green  color  (Hydra*  viridis5),  and  the  other  is  flesh- 
colored  (H.  fusca6).  They  are  found  in  standing  or  slow- 
running  water,  attached  to  submerged  plants,  sticks,  and 
stones.  Throughout  the  winter  they  live  at  the  bottom 
of  ponds,  below  the  ice.  The  body  of  Hydra  is  soft  and 
highly  contractile,  so  that,  when  first  drawn  from  the 
water,  it  appears  like  a  speck  of  jelly.  Left  undisturbed, 
the  animal  expands,  and  its  five  to  eight  tentacles  wave 


j,  hollow;  evrepov,  intestine. 

nettle. 

8  A  key  to  the  principal  subdivisions  of  the  Cnidaria  and  especially 
of  the  Hydromedusse  will  be  found  in  the  Appendix  to  this  Chapter. 
4  i;5/>a,  a  mythological  monster,  capable  of  regenerating  its  head. 
6  Green.  «  Brown. 

205 


206 


ZOOLOGY 


slowly  about  in  search  of  food.  The  tentacles  are  richly 
supplied  with  nettling  cells,  each  of  which  contains  a 
fluid-filled  capsule,  in  which  is  coiled  a  thread-like  tube. 


FIG.  192.  —  Sycon  gelatinosum.  A  portion  slightly  magnified :  one  cylinder 
(that  to  the  right)  bisected  longitudinally  to  show  the  central  stomach 
cavity  opening  on  the  exterior  by  the  osculum,  and  the  position  of  the  incur- 
rent  and  radial  canals ;  the  former  indicated  by  the  black  bands,  the  latter 
dotted,  ip  marks  the  position  of  three  of  the  groups  of  inhalant  pores  at 
the  outer  ends  of  the  incurrent  canals;  6,  osculum. 

When  stimulated  by  contact  with  some  foreign  body  the 
tentacle  closes  around  it,  while  from  each  capsule  the 
lasso-thread  rolls  out  as  the  finger  of  a  glove  is  rolled 
inside  out,  and  discharges  the  irritating  poison  through 


THE  HYDRA   AND  ITS  ALLIES 


207 


the  lumen  of  the  thread.  If  a  small  animal  has  been  the 
irritant,  it  is  instantly  caught  in  the  thread,  paralyzed  by 
the  poison,  and  soon  conveyed  to  the  Hydra's  mouth. 
The  principal  food  of  Hydra  is  small  worms  and  the 
smaller  Crustacea,  such  as  Daphnia  and  Cyclops. 


FIG.  193.  —  A  colony  of  Cordylophora  lacustris,  on  a  shell  of  Mytilus.  For 
clearness,  a  number  of  the  erect  branches  are  cut  off  at  the  stolon,  a,  very 
young1  shoot  without  lateral  branches;  b,  young  stock  with  lateral  branches 
but  no  gonophores ;  c,  a  stock  with  gonophores  on  lateral  branches ;  d,  fully 
grown  stock  with  lateral  stems.  After  Schulze. 

Fresh-water  Cnidaria  are  of  extremely  few  kinds. 
Hydra  was  once  regarded  as  the  only  instance,  but 
others  are  now  known.  One  of  these,  called  Cordylo- 
phora, is  found  chiefly  in  brackish  water  or  in  fresh  water, 
near  the  coast.  Like  many  of  the  marine  hydroids,  Cordy- 


208  ZOOLOGY 

lophora  produces  its  young  in  special  capsules,  called 
gonophores,  which  are  rudimentary  jelly-fishes  (Fig.  193). 
The  young  become  free  when  they  have  gained  an  elon- 
gated, cylindrical  form.  There  are  other  fresh-water 
species  which  have  free  jelly-fishes.  In  this  country  we 
have  a  species,  Microhydra  l  Ryderi,  hitherto  known  only 
about  Philadelphia,  whose  hydroid  stage  is  extremely 
small  and  bears  no  tentacles.  The  jelly-fishes  are  set 
free  during  July.  Fresh-water  jelly-fishes  have  also  been 
described  from  Lake  Tanganyka,  Africa,  and  from  a  tank 
at  Regent's  Park,  London,  to  which  they  had  doubtless 
been  imported  on  plants.  It  is  very  probable  that  all 
fresh-water  hydroids  which  produce  jelly-fish  have,  geo- 
logically speaking,  recently  come  from  the  sea.  Hydra, 
however,  is  probably  a  long-established  fresh-water  species. 

The  marine  hydroids  are,  in  contrast  to  the  fresh- water 
ones,  very  numerous.  The  Hydrocorallidae 2  are  peculiar 
in  that  they  secrete  a  great  amount  of  calcareous  sub- 
stance, so  that  they  were  formerly  regarded  as  belonging 
to  the  typical  corals  (Scyphozoa).  They  may  be  easily 
distinguished  by  the  absence  of  radial  septse  in  the  cups 
occupied  by  the  hydroid.  Here  belong  the  millepore 
corals  of  Florida. 

The  Tubularidae3  include  some  hydroids  of  large  size, 
single  individuals  of  Tubularia  becoming  six  inches  long. 
Other  species  grow  on  gastropod  shells  which  are  occu- 
pied by  hermit-crabs  (Figs.  194  and  195).  So  thickly  do 
they  grow  that  they  make  a  plush-like  covering  on  the 
upper  part  of  the  shell,  and  they  have  the  curious  habit 

1  Small  Hydra. 

2  Combining  the  qualities  of  Hydra  and  the  corals. 

3  From  tubulus,  a  little  tube. 


THE  HYDRA   AND  ITS  ALLIES 


209 


of  building  out  the  lip  of  the  shell  so  as  to  enlarge  the 
aperture.  They  do  this  in  order  that  the  hermit-crab,  as 
it  grows  larger,  shall  not  be 
forced  to  exchange  the  shell 
for  a  larger  one,  leaving  the 
hydroids  on  the  cast-off  shell 
to  roll  about  on  the  beach 
and  perish. 

Of  the  Campanularidae,1  or 
bell-hydroids,  one  of  the 
common  representatives  is 
Obelia,2  which  may  be  found 
at  low  tide  hanging  from 
rocks  beneath  seaweed,  and 
looking  like  delicate  white 
threads  (Fig.  196).  Observed 


FIG.  194.  —  Stylactis,  a  tubularian 
hydroid,  growing  on  a*snail.  Nat. 
size.  Photo,  of  living  animal  by 
W.  H.  C.  P. 


FIG.  195.  —  Hydractinia,  a  tubularian  hydroid.  «,  colony  growing  on  gastro- 
pod shell  inhabited  by  a  hermit-crab ;  b,  bit  of  colony  enlarged ;  dz,  modified, 
tactile,  individuals  ;  s,  reproductive  individuals  ;  sp,  spines.  From  Parker 
and  Haswell. 


campanula,  a  little  bell. 


6/3eX6s,  a  spit. 


210  ZOOLOGY 

under  the  microscope    eacli  stem  appears  as    a  series    of 
hydrantlis  placed  in  zigzag  fashion,  one  beyond  the  other. 


FIG.  196.  —  Obelia  ( ?) ,  a  group  of  campanularian  hydroid  colonies.     Nat.  size. 
Photo,  by  W.  H.  C.  P. 

Another   common  kind  is  Sertularia,1  which  forms  rusty 
brown  threads  (Fig.  197).     All  the  hydrantlis  of  one  stem 

occur     in    one    plane    and 
oppositely. 

Both  tubulariaii  and 
campanularian  hydroids 
may  give  rise  to  jelly-fishes. 
These  jelly-fishes  are  formed 
as  buds  on  the  hydraiith,  and 
after  they  become  able  to 
move  of  themselves  they  are 

FIG.  197.  —  Sertularia,  a  small  colony. 

1.5  nat.  size.  cut  oft  from  the  parent  and 

1  Derived  from  serta,  garland. 


THE  HYDRA   AND  ITS  ALLIES 


211 


swim  away.  The  jelly-fishes  then  give  rise  to  the  sexual 
products  and  discharge  them  into  the  water  (Fig.  198). 
In  other  cases  the  jelly-fish  is  formed  but  never  separated 


FIG.  198.  —  Bougainvillea  ramosa.  A,  entire  colony,  natural  size;  B,  portion 
of  the  same  magnified;  C,  immature  medusa;  dr.  c,  circular  canal;  cu, 
cuticle  or  perisarc ;  ent.  cav,  enteric  cavity ;  hyd,  polyp  or  bydranth;  hyp, 
hypostome  or  manubrium ;  med,  medusa;  mnb,  manubrium ;  rad.  c,  radial 
canal;  t,  tentacle;  v,  velum.  From  Parker's  "Biology,"  after  Allman. 
This  is  closely  allied  to  the  New  England  B.  supercilians. 


212  ZOOLOGY 

from  the  parent,  and  the  eggs  develop  in  the  bud.  In 
still  other  cases  a  mere  bud,  called  gonophore,  is  formed, 
which  becomes  full  of  sexual  products  without  ever  ac- 
quiring resemblance  to  a  jelly-fish.  The  jelly-fish  is  the 
primitive  type  which  has  undergone  a  reduction  in  some 
cases  to  a  gonophore.  It  is  an  interesting  fact  that  in 
certain  species  sometimes  jelly-fishes  and  sometimes  gono- 
phores  will  be  produced.  In  the  Campanularidse  the 


FIG.  199.  —  Zygodactyla.    Reduced.    From  a  drawing  by  A.  A^assiz. 

gonophores  are  encased  in  a  cuticular  capsule,  but  in  the 
Tubularidee  they  are  quite  naked. 

There  are  certain  hydromedusae  in  which  the  hydroid 
stage  is  unknown  or  known  to  be  lacking.  Here  belong 
some  jelly-fishes  of  large  size,  like  Zygodactyla,  one  of  the 
Trachomedusse  of  our  coast,  which  may  become  eight  to 
ten  inches  in  diameter  (Fig.  199).  Besides  these  the  sea 
contains  many  small  species,  which  are  easily  captured  in 
the  net,  and  which  are  of  extreme  beauty  and  delicacy. 

Besides  the  Hydromedusse,  the  group  of  Hydrozoa  in- 
cludes the  Siphonophora.1  These  animals  are  always 
colonial  and  free-swimming,  and  are  among  the  most 

1  <ri(f)(i)v,  a  siphon  ;  0op6s,  bearing. 


THE  HYDRA   AND  ITS  ALLIES 


213 


beautiful  inhabitants  of  the  sea.     Those  who  have  crossed 
the  Atlantic  are  acquainted  with  the  "  Portuguese  man-of- 


FIQ.  2QO.  —  Physalia  arethusa. 
Nat.  size.     After  Agassiz. 


ntc 


FIG.  201.  —  Hahstemma  tergt- 
stinutn.  The  entire  colony. 
coe,  cosnosarc;  dz,  dactyle- 
zooid  ;  hph,  hydrophyllium  or 
bract;  net,  nectocalyx  or  swimming-bell ;  ntc,  battery  of  nematocysts; 
p,  polyp;  pn,  pneumatophore  or  float;  t, tentacle.  After  Glaus. 


214  ZOOLOGY 

war"  (Physalia,1  Fig.  192),  which  often  swarms  in  the 
Gulf  Stream.  The  huge  float  which  lies  on  the  surface 
of  the  water  serves  also  as  a  sail  by  which  the  animal  is 
transported  by  the  wind.  There  are  other  smaller,  more 
graceful  species  of  more  typical  form  (Fig.  201).  The 
structure  of  a  siphonophore  is  very  complex.  From  the 
float  hangs  a  central  stem.  Upon  this  stem  are  budded 
feeding  zooids  —  hydranth-like  forms  provided  with  mouth 
and  tentacles  —  and  reproductive  zooids  —  gonophore-like 
forms  which  produce  the  germ  cells.  There  are  leaf  -like 
expansions  also,  which  are  rudimentary  medusae.  All  the 
many  forms  budded  on  the  stem  are  modifications  of  the 
hydroid  type. 

Contrasted  with  the  Hydrozoa  are  the  Scyphozoa,2  which 
are,  on  the  whole,  larger  animals.  These,  too,  occur  both 
in  the  sessile,  polyp  form  and  in  the  jelly-fish  form.  The 
sea-anemones  are  common  examples  of  the  polyp.  These 
are,  for  the  most  part,  solitary,  fleshy  creatures,  often 
brilliantly  colored,  and  therefore  appropriately  called  by 
the  Germans  "  sea-roses,"  and  in  this  country  and  in  Eng- 
land "  sea-anemones."  They  are  of  cylindrical  form,  bear 
a  circle  of  tentacles  around  the  mouth  at  the  upper  end, 
and  have  a  muscular  base  by  which  they  attach  themselves. 
They  vary  in  diameter  from  one-sixth  of  an  inch  to  two 
feet.  Some  species  live  in  the  sand,  out  of  which  they  get 
some  organic  food,  and  at  least  one  species  (Minyas9)  is 
free-swimming. 

Our  commonest  Northern  sea-anemone  is  Metridium 
marginatum  (Fig.  202),  which  occurs  on  rocky  shores  south 


bladder.  2  o-/ci50os,  cup  ;  fwov,  animal. 

3  For  a  figure  of  Mint/as,   see  Parker  and  Haswell,    "Text-book  of 
Zoology,"  p.  189,  Fig.  139. 


THE  HYDE  A   AND  ITS  ALLIES 


215 


to  New  Jersey,  but  reaches  its  maximum  development 
along  the  coast  of  Maine.  It  varies  greatly  in  color,  some 
individuals  being  white,  others  salmon-colored  or  olive. 
The  flat  upper  surface  bears  the  slit-like  opening  to  the 
internal  sac.  Either  one  or  both  angles  of  this  slit  have 
thickened  edges,  and  corresponding  to  this  difference  is  a 


FIG.  202.  —  Metridium,  one  of  our  sea-anemones.      Two   individuals  shown 
expanded.    Photo,  of  the  living  animals  in  the  water,  hy  W.  H.  C.  P. 

difference  in  the  internal  structure.  Inside,  the  central 
cavity  is  separated  into  compartments  by  radial  partitions. 
The  coral  polyp  does  not  differ  essentially  from  Metri- 
dium.  But  it  has  the  habit  of  secreting  lime  at  its  base, 
so  that,  in  course"  of  time,  a  high  cup  is  built  up.  The  top 
of  the  cup  bears  radial  septa,1  which  are  laid  down 

i  Fig.  203. 


216 


ZOOLOGY 


in   the    interspaces   between   the    fleshy   partitions   men- 
tioned in  speaking  of  Metridium.     Since  most  corals,  like 


FIG.  203.  —  Coral  cup  of  manicina.     Nat.  size.    Photo,  by  W.  H.  C.  P. 

hydroids,  bud  freely,  and  since  every  bud  secretes  coral  at 
its  base,  an  extensive  and  complicated  limy  mass  may  be 
produced.  This  is  the  way  in  which  the  brain  corals  and 


FIG.  204.  —  Astranyia  danse,  a  cluster  of  our  Northern  coral-polyps,  resting 
on  limy  bases  of  their  own  secretion.  The  animals  are  extremely  delicate 
and  transparent.  From  a  lithograph  by  Louis  Agassiz's  artist  Sonrel. 

branching  corals  are  formed.  The  only  coral  of  the  north- 
eastern United  States  is  Astrangia  dance,  which  occurs 
north  to  Cape  Cod.  It  is  a  beautifully  transparent  species, 
and  forms  thin  encrustations  of  limy  matter  (Fig.  204). 


THE  HYDRA   AND  ITS  ALLIES  217 

Coral  reefs  are  almost  exclusively  the  product  of  coral 
polyps  modified  by  the  environmental  conditions.  The 
reef -building  corals  live  in  shalloAV  water  from  loAv-water 
mark  to  a  depth  of  one  hundred  feet  only.  Their  dis- 
tribution along  the  coast  line  depends  upon  the  winter 
temperature  of  the  sea,  since  they  cannot  live  at  a  tem- 
perature below  20°  C.  ;  consequently  reef -building  corals 
are  confined  to  warm  latitudes.  However,  tropical  shores 
which  are  washed  by  arctic  currents,  such  as  the  west 
coasts  of  Africa  and  South  America,  are  destitute  of  coral 
formations.  On  the  other  hand,  shores  in  the  temperate 
zone  that  are  washed  by  tropical  currents,  such  as  our 
Florida  coast  which  is  washed  by  the  Gulf  Stream,  may  be 
rich  in  coral  reefs.  Corals  demand  undiluted  sea-water, 
hence  they  do  not  thrive  in  harbors  which  receive  the 
waters  of  great  rivers — a  circumstance  of  great  impor- 
tance for  the  commerce  of  tropical  countries.  Moreover, 
corals  require  a  rock  bottom  on  which  to  build,  and  they 
cannot  gain  a  foothold  on  shores  where  the  cliffs  descend 
precipitously  to  great  depths.  Coral  reefs  receive  dif- 
ferent names  according  to  their  varying  relations  to  the 
shore.  Fringing  reefs  are  found  close  to  the  shore  line. 
Barrier  reefs  lie  at  some  distance  from  land,  with  a  body 
of  quiet  water  between  them  and  the  shore.  An  Atoll  is 
a  further  step,  in  which  a  small  island,  formerly  sur- 
rounded by  a  barrier  reef,  has  disappeared,  leaving  a  cir- 
cular reef  surrounding  a  body  of  water  (Fig.  205). 
Exactly  how  the  central  land  disappears,  whether  by  sub- 
sidence of  the  sea  floor  as  the  reef  grows  up  or  by  being 
washed  away,  is  still  a  matter  of  dispute. 

Budding  and  the  Formation  of  Colonies.  — The  Ciiidaria 
are  one  of  three  groups  of  animals  which  have  the  habit  of 


218  ZOOLOGY 

forming  colonies  by  budding,  somewhat  after  the  fashion 
of  plants.  The  other  groups  are  the  Bryozoa,  or  "sea- 
mats,"  and  the  Timicata,  or  " sea-squirts."  In  all  cases 
the  buds  arise  from  a  definite  part  of  the  parent  body  and 
develop  into  a  definite  form,  often  exactly  like  that  pro- 
duced from  the  egg.  When  the  buds  remain  attached  to 
the  parent,  a  compound  individual  or  colony  is  produced. 
These  colonies  differ  greatly  in  form.  Thus  among  liy- 
droids  we  have  colonies  which  produce  runners,  from  which 
alone,  and  not  from  other  hydranths,  new  hydranths  arise. 


FIG.  205.  —  Atoll  in  Fiji  Islands  (Nanuku  Levu).  The  large  circle  of  white 
made  by  breakers  indicates  the  position  of  the  coral  reef.  A  small  bit  of 
land  still  remains  in  the  interior  lagoon.  Photo,  by  Dr.  W.  McM.  Wood- 
worth.  From  A.  Agassiz,  "  Coral  Reefs  of  Fiji." 

In  another  case  (Obelia),  one  hydroid  buds  from  the  side 
of  another  and  rises  beyond  it,  continuing  the  main  stem 
of  the  colony.  Since  its  descendants  do  the  same,  the  stalk 
is  made  up  of  successive  generations  of  hydranths.  Some- 
times the  hydranths  are  placed  close  together  and  oppo- 
site, like  the  leaves  of  Arbor  vitse  (Sertularia,  Fig.  197). 
Again,  there  may  be  a  main  stalk  composed  of  one  hy- 
dranth  and  a  series  of  lateral  branches  in  one  plane,  mak- 
ing a  fan-like  arrangement  of  the  colony.  Or  the  lateral 
branches  may  arise  in  any  plane,  producing  a  bushy  colony. 


THE  HYDE  A   AND  ITS  ALLIES 


219 


The  variety  in  the  form  of  the  colony  possessed  even  by  a 
single  species  adds  to  the  diversity  of  hydroids. 

The  Ctenophora,  or  sea-walnuts,  are  a  small  group  of 
exclusively  marine  organisms  which  float  on  the  surface 
of  the  sea,  and  like  most  animals  having  this  habit  have 
become  clear  as  glass.  Many  of  them  are  highly  phos- 
phorescent (Fig.  206). 

In  any  colony  a  division  of  labor  may  occur  among  the 
constituent  individuals,  or  zooids.  Thus  in  the  simplest 
cases  we  have  crawling  zooids, 
or  stolons,  and  feeding  zooids. 
In  Hydractinia1  we  have,  in  addi- 
tion, reproductive  zooids,  nettling 
zooids,  and  passive,  thorn-like 
zooids.  Here  we  see  how  com- 
pletely subservient  the  individual 
is  to  the  good  of  the  community. 
This  subserviency  has  ruled  in  all 
successful  colonies  of  animals. 

Regeneration.  —  Closely  allied  to 
the  power  of  budding  is  that  of 
reproducing  a  lost  organ.  Suppos- 
ing the  "head"  (mouth  and  ten- 
tacles) of  a  Hydra  to  be  cut  off,  the 
base  will  reproduce  the  lost  head.  Suppose  the  base  to  be 
removed,  the  head  will  reproduce  a  new  base.  When  a 
Hydra  is  cut  in  two  transversely,  two  Hydras  result  where 
formerly  there  was  only  one.  Even  three  or  more  Hydras 
may  arise  when  a  Hydra  has  been  cut  into  so  many  pieces. 
Where  other  conditions  are  favorable  to  life,  you  can 
hardly  kill  a  Hydra  by  mutilation.  A  trace  of  this 

i  Tig.  195. 


FIG.  206.  —  Idylia,  a  sea- 
walnut,  seen  from  the 
broad  side.  Half  nat.  size. 
a,  anal  opening ;  b,  lateral 
tube ;  c,  circular  tube ;  d,  c, 
/,  g,  h,  rows  of  paddles. 
After  Agassiz. 


220 


ZOOLOGY 


capacity  for  regeneration,  as  it  is  called,  is  seen  also  in 
man  when  a  wound  heals,  and  a  diseased  organ,  even  when 
partly  destroyed,  is  made  whole  again. 


APPENDIX   TO   CHAPTER   XIV 


KEY    TO    THE    PRINCIPAL    SUBDIVISIONS    OF    THE    CNIDAKIA 


c*i.    Body  composed  of  4,  6,  or  many  rays ;   nettling 
organs  well  developed. 

61.  Mouth   at  apex  of  an  oval  cone ;    cavity 

simple  .         .         .         .         .         .     Class 

Ci.  Existing  for  the  most  part  in  2  forms ; 
a  sessile  one,  hydroid ;  and  a  free- 
swimming  one,  medusa.  The  hydroid 
form  is  sessile  ;  the  medusse  are 
mostly  small,  or  may  remain  at- 
tached to  the  hydroid  .  Order 
C2.  Free-swimming  colonies  composed  of 
hydroid  and  medusoid  individuals 
budded  on  a  floating  stem  .  Order 

62.  Mouth  at  bottom  of  an  oral  crater  ;  cavity  di- 

vided by  radial  partitions.  The  more  com- 
mon forms  are  large  jelly-fishes    .     Class 
«2.    Body  composed  of  2  radii,    with  8  meridional 
rows  of  plates  of  cilia  ;  nettling  capsules  modi- 
fied to  form  adhesive  organs        .        .     Class 


Hydrozoa 


Hydromedusce 


Siphonophora 

(Portuguese  man- 
of-war,  etc.) 


8cyphozoa 


Ctenophora 

(Sea-walnuts) 


KEY  TO  THE  FAMILIES  OF  THE  HYDROMEDUS^ 


a\.    Hydroid  individuals,  without  cuticula  or  stolons ; 
fresh  water       .         .        .        .        ... 

a2'    Hydroid  individuals,  if  present,  with  cuticula  or 
stolons;  marine. 


Hydroidm 

(Ex.  Hydra) 


APPENDIX  TO   CHAPTER   XIV 


221 


61.    Hydroids    present ;    medusae   without  free 

auditory  clubs. 

Ci.    Hydrflid  stocks,    with    calcareous   ex- 
ternal skeleton  ;  no  free  medusse      .     Hydrocorallidce 
c2.    Hydroid  heads  never  enclosed  in  cuticu- 
lar  cup ;   medusse,  if  free,  without 
marginal  vesicles  ;  gonads  on  manu- 

brium Tubularidw 

c3.    Hydroid  heads  enclosed  in  calyx ;  me- 
dusae, if  free,  with  gonads  on  radial 

canals Campanularidce 

b-2.    Hydroids  absent ;  medusse  with  free-stand- 
ing auditory  clubs. 

ci.    Gonads  on  radial  canals       .        .        .      Trachomedusce 
c2.   Gonads  on  manubrium          .         .         .       Narcomedusce 


CHAPTER   XV 
THE  PARAMECIUM  AND  ITS   ALLIES 

PABAMECIUM1  belongs  to  the  Protozoa,2  the  lowest 
group  of  animals,  characterized  by  the  fact  that  the  body 
contains  no  specialized  tissues  and  organs,  but  is  made 
up  of  a  single  cell,  and  is  usually  microscopic.  Protozoa 
live  in  water  or  in  moist  situations.3 

The  Infusoria  were  unknown  to  man  until  the  latter 
half  of  the  seventeenth  century,  when  a  Dutch  naturalist 
named  Leeuwenhoek,  by  means  of  the  newly  invented 
compound  microscope,  studied  and  described  several  kinds 
which  he  had  found  in  standing  water  and  called  animal- 
cules or  water  insects.  As  the  microscope  became  per- 
fected, progress  was  made  in  the  study  of  these  organisms, 
but  even  in  the  early  half  of  our  century  several  eminent 
zoologists  maintained  that  the  Infusoria  possessed  digestive, 
neural,  haemal,  and  reproductive  organs.  The  proper 
structure  of  the  Infusoria  has  been  generally  recognized 
only  within  the  last  fifty  years. 

The  conceptions  formerly  entertained  concerning  the 
origin  of  Infusoria  were  as  erroneous  as  those  relating  to 
their  internal  structure.  These  erroneous  conceptions 
were  an  inheritance  from  a  time  when  even  scientific  men 

1  Trapa/i^/c^s,  somewhat  long. 

2  TT/OWTOJ,  earliest ;  fa>ov,  animal. 

8  Keys  to  the  four  classes  of  Protozoa  and  to  the  orders  of  Infusoria  will 
be  found  in  the  Appendix  to  this  Chapter,  page  229. 

222 


THE  PAEAMECIUM  AND  ITS  ALLIES  223 

held  that  many  of  the  larger  animals,  such  as  eels,  bees, 
and  flies,  were  generated  without  parents.  This  was  the 
theory  of  "spontaneous  generation."  In  time  this  theory 
became  much  more  restricted.  It  was  found  that  the 
maggots  in  putrid  meat  are  not  generated  "spontaneously" 
out  of  the  meat,  but  are  derived  from  flies'  eggs,  and,  in 
their  turn,  develop  into  fertile  flies.  But  the  idea  that 
Infusoria  are  formed  out  of  inorganic  material  continued 
to  be  held  until  much  more  recently,  until  Pasteur,  Tyn- 
dall,  and  others  demonstrated  that  fluids  heated  to  a 
sufficiently  high  temperature  for  a  sufficient  time,  and 
then,  while  hot,  sealed  from  contact  with  air,  do  not 
develop  Infusoria,  no  matter  how  long  they  may  be  kept. 
This  method  of  excluding  Infusoria  and  other  minute 
organisms,  especially  bacteria,  is  employed  to-day  in  can- 
ning meat,  vegetables,  and  fruit.  The  experiments  re- 
ferred to  gave  a  death-blow  to  the  theory  of  spontaneous 
generation,  and  led  to  the  conclusion  that  all  Infusoria  are 
derived  from  living  germs. 

Whence  the  living  germs  come  which  enter  the  water 
it  is  not  difficult  to  determine.  Many  Infusoria  can  pass 
into  a  quiescent  "  spore  "  stage  in  which  they  may  be  dried 
and  blown  about  without  loss  of  life.  Dry  grass,  straw, 
and  other  substances  contain  some  of  the  germs,  and  others 
float  in  the  air  and  fall  as  dust  into  the  water.  Even 
drinking  water  may  contain  here  and  there  an  infusorian 
or  its  germ.  When,  therefore,  one  fills  a  clean  vessel 
with  pure  water,  and  puts  hay  or  dry  leaves  in  it,  and  lets 
it  stand  open  to  the  air  in  a  warm  place,  the  result  is 
pretty  sure  to  ba  that  germs  develop  in  the  mixture. 
The  heat  and  the  organic  infusion  merely  facilitate  this 
development. 


224 


ZOOLOGY 


Of  all  the  Infusoria,  none  is  more  abundant  than  Para- 
mecium.  It  occurs  everywhere,  principally  in  stagnant 
fresh  water,  but  also  in  salt  water.  It  lives  entirely  on 
vegetable  food,  and  is  sure  to  abound  wherever  plant 
matter  is  undergoing  decay.  When  a  culture  is  once 


FIG.  207.  —  Carchesium,  a  stalked  Vorticella.     Greatly  magnified, 
photograph  of  the  living  animals. 


From  a 


started  from  a  hay  infusion,  —  which  takes  one  or  two 
weeks, — it  will  be  found  to  thrive  especially  on  corn-meal. 
As  an  example  of  the  Heterotricha,  Stentor,1  the  trumpet- 
animalcule,  may  be  mentioned.  Stentor  is  found  attached 
to  vegetable  debris  —  sticks,  stones,  water- weeds,  and  other 
objects  —  occurring  in  pools,  ponds,  lakes,  and  sluggish 
streams.  These  things  should  be  gathered  and  placed  in 

a  Greek  at  Troy,  known  for  his  loud  voice. 


THE  PARAMECIUM  AND  ITS  ALLIES  225 

an  aquarium,  when  the  Stentors,  if  present,  will  attach 
themselves  to  the  glass  sides  of  the  vessel.  The  attach- 
ment of  Stentor  to  objects  is  not  permanent,  for  it  may 
loose  its  hold  and  swim  free.  When  the  animal  is  stained 
in  haematoxylin,  the  characteristic  nucleus,  looking  like  a 
chain  of  beads,  becomes  evident. 

Vorticella,1  the  bell-animalcule,  is  found  in  pools  or 
infusions,  permanently  attached  by  a  long  stalk.  When 
the  animal  is  irritated,  it  contracts  its  stalk,  which  twists 
into  a  close  spiral.  Carchesium  2  differs  from  Vorticella,  in 
forming  colonies,  so  that  a  number  of  heads  are  attached 
to  a  central  stalk.  A  colony,  when  fully  expanded,  appears 
like  a  fine,  white  mould  attached  to  a  submerged  object. 
In  both  of  these  types  the  food  consists  of  small  organic 
particles,  which  are  swept  into  the  gullet  by  the  circlet  of 
cilia  placed  around  the  upper  end  of  the  body. 

The  Suctoria3  are  sessile  Infusoria,  from  whose  upper 
surface  numerous  remarkable  sucking-tentacles  arise.  By 
means  of  these  tentacles  the  animal  can  hold  on  to  Para- 
mecia  and  other  free-swimming  Infusoria,  from  which  it 
extracts  the  body  fluids.  Some  Suctoria  are  stalked  (e.g. 
Podophora*),  while  others  are  unstalked  (e.g.  Acineta^. 
They  are  found  most  abundantly  in  standing  water,  either 
fresh  or  salt,  and  are  often  attached  to  other  animals,  — 
Bryozoa,  entomostracans,  and  pulmonate  mollusks. 

Of  the  group  Flagellata,6  or  lash-animalcules,  Euglena7 
is  a  common  representative  .  It  is  of  microscopic  size,  but 
occurs  in  such  numbers  as  often  to  give  a  decided  green 

1  Dim.  from  vortex,  whirlpool.  4  Trofo,  foot ;  6<j>pfc,  eyebrow. 

2  Kapx'/i<riov,  goblet,  Fig.  207.  5  d/c^ros,  without  movement. 

3  From  sugere,  suctum,  to  suck.  6  flagellum,  a  lash. 

7  s,  with  a  beautiful  eye. 


226 


ZOOLOGY 


color  to  the  pools  of  water  it  inhabits.  It  is  spindle- 
shaped,  and"  bears  a  flagellum  at  its  anterior  end.  At  the 
base  of  the  flagellum  is  a  red  "eyespot." 

Allied  to  Euglena  is  Volvox,1  a  spherical,  multicellular 


FIG.  208.  — Euylena  virldis;  a  lash-animalcule.  A-D,  four  views  illustrating 
the  characteristic  movements ;  E  and  H,  enlarged  views  of  adult ;  F,  out- 
line of  anterior  end  further  enlarged ;  G,  resting  stage ;  cy,  cyst ;  fl ,  flagel- 
lum; m,  mouth;  nu,  nucleus;  <e,  gullet;  pg,  pigment  spot;  r,  reservoir. 
After  Kent  and  Klebs. 


organism,  half  animal  and  half 
plant,  and  forming  a  sort  of  con- 
necting link  between  the  Pro- 
tozoa (or  one-celled  animals)  and 
the  multicellular  higher  organ- 
isms. Volvox  occurs  abundantly 
in  our  ponds  and  gets  its  name 
from  its  manner  of  revolving  in 
the  water  (Fig.  209). 

Very  different  in  habitat  from 


FIG.  209.  —  Volvox  ylobator. 
Much  magnified.  Photo, 
of  the  living  animal. 


1  From  volvere,  to  roll. 


THE  PAEAMECIUM  AND  ITS  ALLIES 


227 


the  foregoing  are  the  Sporozoa,1  which  are  minute  rod- 
like  organisms,  occurring  as  parasites  in  the  body  of 
various  kinds  of  higher  animals,  especially  in  the  food- 
tract.  They  increase  by  transverse  division  of  their  rod- 
like  bodies ;  but  periodically  they  encyst,  and  divide  into 
numerous  "  spores,"  which,  under  favorable  conditions,  are 
set  free  in  great  numbers. 


FIG.  210. — Amoeba,  the  proteus  animalcule.  Greatly  magnified,  n,  the 
nucleus ;  10.  v,  water  vacuoles ;  c.  v,  contractile  vacuoles;  /.  v,  food  vacuoles. 
E.  B.  Wilson,  "  The  Cell." 

Of  all  Protozoa,  probably  the  simplest  is  Amoeba.2  This 
type  varies  greatly  in  size,  from  0.02  mm.  to  about  0.3  mm. 
It  appears  as  a  clear,  highly  refractive  body  of  changing 
outline.  The  body  does  not  look  homogeneous  when 
viewed  with  a  high  power,  but  contains  various  granules 
derived  from  ingested  food,  vacuoles  of  water,  and  a  trans- 
parent, slightly  more  d^nse,  spherical  or  ellipsoidal  body, 

1  <T7r6/)05,  spore  ;  {a>ov,  animal, 
alteration. 


228  ZOOLOGY 

the  nucleus,  which  it  is  often  difficult  to  make  out  on  the 
living  animal.  The  whole  substance  of  the  Amceba  is 
mobile,  so  that  the  internal  organs  have  no  fixed  relation 
to  one  another.  Quantities  of  Amoeba  can  usually  be 
obtained  for  study  by  gathering  the  mud  from  the  edges 
of  stagnant  pools,  or  by  scraping  the  green  growth  from 
flower-pots,  and  letting  these  gatherings,  covered  with  a 
little  water,  stand  in  a  fairly  warm  place  for  two  or  three 
weeks. 

Even  the  Protozoa  bear  important  relations  to  man. 
One  species,  Amceba  coli,  has  long  been  known  occasion- 
ally to  inhabit  the  food  canal  of  man,  and  it  is  now  known 
that  an  amoebiform  organism  (probably  one  of  the  Sporo- 
zoa)  is  the  cause  of  malarial  diseases.  Since  in  one 
common  species  48  hours  are  required  to  complete  a 
developmental  cycle,  the  recurrence  of  the  fever  every 
alternate  day  is  explained.  It  is  now  demonstrated  that  at 
least  one  of  the  common  agents  in  infection  with  malaria 
is  the  mosquito,  which  carries  the  germs  of  the  malaria 
parasite  from  one  host  to  another.  Other  Sporozoa,  of  at 
least  one  species,  are  parasitic  in  the  human  liver,  others 
attack  fish  and  cause  them  to  die  in  large  numbers;  still 
others  cause  sickness  and  death  among  domesticated 
animals.  The  Texas  fever  among  cattle  is  believed  to  be 
caused  by  an  organism1  belonging  to  this  group,  the 
inoculation  of  the  cattle  being  effected  by  the  cattle-tick. 

The  reproductive  capacity  of  Protozoa  is  so  great  that 
their  importance  in  the  world,  despite  their  small  size,  is 
not  astonishing.  One  of  the  early  students  of  Protozoa, 
Ehrenberg,  computed  that  from  one  individual  of  Para- 
mecium  aurelia  268,000,000  might  be  developed  in  one 

1  Called  Piroplasma  bigeminnm. 


APPENDIX  TO   CHAPTER  XV  229 

month  by  the  process  of  division.  Apparently  the  divi- 
sion cannot  go  on  indefinitely,  but  from  time  to  time  the 
Paramecia  unite  temporarily  in  pairs  and  undergo  an 
exchange  of  some  of  their  nuclear  matter.  This  is  doubt- 
less the  beginning  of  what  is  known  in  the  higher  animals 
as  sexual  reproduction. 


APPENDIX   TO   CHAPTER   XV 

KEY  TO  THE  FOUR  CLASSES  OF  PROTOZOA 

a\.     Without  non-retractile  appendages. 

61.     With  retractile  pseudopodia    .        .  •      -.        .    .     Ehizopoda 

(Ex.  Amoeba) 

Z>2.     Without  pseudopodia ;  covered  with  an  im- 

perf orate  cuticula ;  parasites       .       :.        ,  Sporozoa 

«2.     With  non- retractile  appendages. 

61.     No  cilia,  but  with  one  or  more  flagella    .        ,         Flagellata 

(Ex.  Euglena) 

&2'     With  cilia,  or  sucking  tentacles       .        ,.        .  Infusoria 

(Ex.  Paramecium) 

KEY   TO    THE    SUBCLASSES    AND    ORDERS    OF    INFUSORIA 

a\.     With  vibratile  cilia  and  no  sucking  tentacles          *  -  CILIATA 

61.     Body  everywhere  closely  beset  with  cilia. 

GI.     No  adoral  zone         .        .        ...        »  ___  Holotriclia 

(Ex.  Parameciurn) 

c2.     Adoral  zone  present        .  •      ...      Heterotricha 

(Ex.  Stentor) 

62-     Body  only  partly  ciliated. 

d.     Cilia  limited  to  ventral  side  .      .  .        .        Hypotricha 

c2.     Cilia  form  a  circlet  around  or  at  upper 

edge  of  animal      .        .  .                .          Peritricha 

(Ex.  Vorticella) 

a2.     With  sucking  tentacles  .        .        .        .        .        .          SUCTORIA 


CHAPTER   XVI 

THE   SMELT  AND   ITS   ALLIES 

THE  smelt  is  one  of  the  class  of  fishes.1  This  class  com- 
prises vertebrates  that  breathe  by  means  of  gills  and  do 
not  use  their  appendages  for  walking. 

The  smelts,  which  belong  to  the  salmon  family,  are  pre- 
eminently inhabitants  of  the  northern  temperate  zone, 
since  all  but  one  of  the  ten  genera  occur  only  there..  They 
are  small  marine  fishes,  and  although  a  few  are  inhabitants 
of  the  deep  sea,  most  live  near  the  shore,  and  in  the  spring 
ascend  rivers  to  spawn.  Some  of  them  have  become  cut 
off  from  descending  to  the  sea  and  live  permanently,  as 
"  land-locked  "  forms,  in  fresh  water.  Such  "  land-locked  " 
individuals  are  of  smaller  size  than  the  marine  ones.  The 
food  of  smelts,  like  that  of  other  Salmonidse,  is  chiefly 
animal,  consisting  of  smaller  fishes  or  insects,  small  crusta- 
ceans, and  mollusks. 

Smelt  are  of  considerable  economic  importance,  since 
they  share  with  other  members  of  the  salmon  family  a 
delicately  flavored  flesh.  Our  Atlantic  form,  Osmerus 2 
mordax?  which  ranges  from  Delaware  Bay  northward,  is 
caught  most  abundantly  in  Maine.  The  total  Atlantic 

1  Keys  to  the  principal  orders  of  fishes  and  the  six  suborders  of  the 
Teleostei  will  be  found  at  the  end  of  this  Chapter,  page  252. 

2  6<r/j,T)p6s,  odorous  ;  the  Greek  name  is  the  equivalent  of  the  English 
"smelt."  3  Biting. 

230 


THE  SMELT  AND  ITS  ALLIES  231 

smelt  fishery  is  valued  at  1125,000.  Smelt  eggs  are  arti- 
ficially hatched  and  planted  in  rivers  previously  unin- 
habited by  them.  Smelt  are  said  to  return  to  these  rivers 
after  spending  the  winter  in  the  sea.  The  early  settlers 
on  our  Eastern  coast,  like  the  Indians  before  them,  used 
smelt  to  fertilize  the  land.  At  present  this  wasteful  pro- 
ceeding is  illegal ;  but  the  bones  and  scraps  from  the 
canning  factories  are  used  to  make  commercial  fertilizers, 
since  they  are  rich  in  phosphorus  —  an  important  plant 
food. 

The  family  Salmonidae  includes  some  of  our  most  im- 
portant food  fishes.  It  is  distinguished  from  other  fami- 
lies of  Physostomi  by  the  circumstances  that  both  ventral 
and  adipose  fins  are  present,  that  both  p  rein  axilla  and 
maxilla  bear  teeth  l  and  form  the  margin  of  the  upper  jaw, 
and  that  the  head  is  naked,  body  scaly,  belly  rounded,  and 
pseudobranchise  present.  Besides  the  smelt  there  are 
numerous  important  species.  The  salmon  proper2  are 
restricted  to  the  north  temperate  and  arctic  regions,  and 
live  either  in  the  sea,  migrating  to  fresh  water  to  spawn, 
or  exclusively  in  brooks  and  lakes.  The  migrations  of 
salmon  from  the  sea  up  the  rivers  are  remarkable..  Hun- 
dreds of  miles  are  sometimes  journeyed,  rapids  swum,  and 
falls  leaped,  for  the  purpose  of  laying  eggs  in  some  remote 
lake.  The  females,  with  their  burden  of  eggs,  have  be- 
come so  exhausted  at  the  end  of  the  migration  that  most, 
or  all  of  them,  die  immediately  after  laying  the  eggs.  On 
the  Atlantic  coast  the  Penobscot  River  has  the  most  im- 
portant run  of  salmon.  The  Pacific  salmon  passes  up  the 
Sacramento  and  Columbia  rivers,  and  up  many  rivers  of 
British  Columbia  and  Alaska.  In  these  rivers  the  fish 
iFig..  211,  2  pi.  212, 


232 


ZOOLOGY 


are  caught  as  they  ascend  to  breed.     Such  is  the  greedi- 
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pass  the  nets  of  the  canning  factories,  and  consequently 


THE  SMELT  AND  ITS  ALLIES 


233 


the  apparently  inexhaustible  supply  of  this  fish  has  been 
immensely  reduced,  and  the  fishery  will  soon  become 
destroyed. 


op 


FIG.  212.  —  Salmo  fario.  a.  I,  adipose  lobe  of  pelvic  fin  ;  an,  anus ;  c.f,  caudal 
fin ;  d.  f.  1,  first  dorsal ;  d.f.  2,  second  dorsal  or  adipose  fin  ;  1. 1,  lateral  line  ; 
op,  operculum ;  pet.  f,  pectoral  fin ;  pv.f,  pelvic  fin  ;  v.f,  ventral  fin.  After 
Jardine. 

The  trout,  of  which  there  are  a  number  of  kinds  on  both 
continents,  is  commercially  much  less  important  than  the 


FIG.  213.  — Coregonus,  the  lake  whitefish.     Much  reduced.    From  Goode. 


salmon  proper.  As  a  result  of  overfishing,  and  the  pollu- 
tion of  streams  by  factories  and  sewage,  this  fish  is  dis- 
appearing from  Eastern  waters. 


234 


ZOOLOGY 


The  whitefish  (Coregonus  *),  of  which  we  possess  many 
species,  is  exclusively  an  inhabitant  of  fresh  water.2  Its 
teeth  are  almost  completely  absent,  or  very  small ;  it  feeds 
almost  exclusively  upon  small  arthropods  and  mollusks. 
It  is  of  very  great  commercial  importance,  its  fisheries 
being  valued  at  nearly  three  million  dollars  a  year. 

Leaving  now  the  Salmonidse,  we  may  briefly  consider 
some  of  the  other  more  important  families  of  bony  fishes. 


FIG.  214.  —  Morone  americana,  the  white  perch.  The  fish  is  searching  for  food 
along  the  bottom  of  the  aquarium,  an  instinct  which  it  shows  in  nature  also. 
About  one-third  nat.  size.  Photo,  of  living  animal  by  Dr.  R.  W.  Shufeldt, 
from  "  Bull.  U.  S.  Fish  Com.,"  1899. 

The  darters  are  spiny-rayed  fishes  of  small  size,  from  four 
to  seventeen  centimetres  long,  brightly  colored,  and  with 
well-developed  pectoral  fins.  They  live  in  clear  streams, 
half  concealed  under  stones,  and  are  most  abundant  in  the 
Mississippi  drainage  basin. 


7,  the  pupil  of  the  eye  ;  ywvia,  angle. 


2  Fig.  213. 


THE  SMELT  AND  ITS  ALLIES 


235 


The  perches  are  a  widespread  family,  represented  in  this 
country  chiefly  by  the  common  yellow  perch  of  the  East, 
the  "  wall-eyed  pike  "  of  the  Great  Lake  region,  and  the 
white  perch  of  the  Atlantic  coast  (Fig.  214).  These  fish 
have  an  oblong,  compressed  body  covered  with  small 
scales  ;  they  are  highly  rapacious,  and  are  believed  to  be 


FIG.  215.  —  Eupomatis  f/ibboftus,  the  common  sunfish.  Two-thirds  nat.  size. 
Photo,  of  living  animal  by  Dr.  R.  W.  Shufeldt,  "  Bull.  U.  S.  Fish  Com.," 
1899. 


destructive  to  the  young  of  other  species  of  fish.  They 
are  esteemed  as  food,  although  fortunately  not  to  the 
extent  of  annihilation. 

The  sunfishes1  have  a  percoid  form,  but  have  only  one 
dorsal  fin  instead  of  two.     They  live  in  fresh  water,  have 

1  Fig.  215. 


236 


ZOOLOGY 


rapacious  habits,  are  brilliantly  colored,  and  build  nests  in 
the  sand,  which  both  male  and  female  watch  over  and 
defend  with  courage.  Some  species 
living  in  the  Great  Lakes  are  known 
as  black  bass  or  rock  bass.  The 
small  New  England  species,  with  the 
brilliant  red  edge  to  the  operculum, 
is  called  pumpkin-seed. 

The  toadfishes  (Fig.  216)  are 
represented  in  our  faunas  by  a 
common  species  which  lives  under 
stones  in  harbors  and  attaches  its 
eggs  to  the  under  side  of  stones.  It 
is  a  vigorous  fighter. 

The  sculpin  (Fig.  217)  is  closely 
related  to  the  toadfish.  Like  the 
latter  it  has  a  broad  head  and  nearly 
scaleless  body.  The  pectorals  are 
large,  and  the  two  dorsals  extend 
along  the  greater  part  of  the  back. 
Allied  to  the  foregoing  is  the  rock  eel  (Fig.  218),  which 
is  sometimes  brought  up  in  the  seine  from  a  depth  of  8  to 
10  fathoms. 


FIG.  216.  —  Batrachus  tau, 
the  toadfish.  Dorsal 
view.  Two-thirds  nat. 
size.  Photo,  by  W.  H. 
C.  P. 


FIG.  217. — Acanthocottus,  the  little  sculpin.     Two-thirds  nat.  size.     Photo, 
by  W.  H.  C.  P. 

The  silversides  are  especially  abundant  along  our  At- 
lantic coast.     They  have  an  elongated,  somewhat  com- 


THE  SMELT  AND  ITS  ALLIES 


237 


pressed  body,  and  a  broad,  bright   silvery  band  on   the 
sides,  against  a  greenish  general  body  color.     The  dorsal 


FIG.  218.  —  Pholis,  the  rock  eel.    Right  side.    Nat.  size.     Photo,  by  W.  H.  C.  P. 

spines  are  slender.  The  fish  swim  near  shore,  in  dense 
schools.  One  species  on  the  Californian  coast  is  known  as 
a  "  smelt,"  and  is  a  good  food  fish. 


FIG.  219.  —  Gasterosteus punyitius,  the  nine-spined  stickleback;  male  (above) 
and  female  near  the  nest  in  rushes.  The  female  is  about  to  deposit  its  eggs 
in  the  nest. 


238 


ZOOLOGY 


The  sticklebacks  are  small,  elongated  fishes,  having  an 
extremely  slender  tail  and  a  large  mouth.  The  dorsal  fin 
is  preceded  by  two  or  more  large  isolated  spines.  The 
fishes  live  in  either  fresh  or  brackish  water.  In  some  of 


FIG.  220.  —  Gastsrosteus  bispinoxns,  the  two-spined  stickleback.     Above,  nest 
with  eggs,  and  male  entering.     Below,  male  depositing  its  mil    on  the  eggs. 

Figs.  219  and  220  are  reproductions  of  water-color  paintings  in  the  Museum 
of  Comparative  Zoology  at  Harvard  College. 

the  species  the  male  builds  an  elaborate  nest  from  bits  of 
aquatic  plants,  firmly  united  by  a  special  mucilaginous 
secretion.  The  nest,  which  is  built  among  the  plants  of 
the  stream,  consists  of  a  short  cylinder,  through  the  hori- 


THE  SMELT  AND  ITS  ALLIES 


239 


zontal  cavity  of  which  the  fish  can  lie  while  it  deposits  its 
eggs.  The  male  is  polygamous,  and  guards  the  single 
nest,  which  receives  the  eggs  from  various  females  (Figs. 
219,  220). 

The  codfishes,  among  the  most  important  of  food  fishes, 
are  characterized  by  having  ventral  fins  without  spines, 
and  articulated  fin-rays,  well-developed  caudal  fin,  isocercal 
tail,  and  barbel  011  chin.  Our  common  codfish  (Fig.  221) 


FIG.  221.  —  Gadus  morrhua,  the  codfish.     About  one-seventh  nat.  size. 
After  Storer. 


occurs  over  the  whole  of  the  North  Atlantic  ;  but  the 
most  important  fishing  localities  are  the  banks  near  New- 
foundland, especially  Grand  Bank. 

The  flatfishes  are  peculiar  among  fishes  in  that  they 
have  the  habit  in  the  adult  stage  of  lying  on  one  side.  In 
consequence  the  under  eye  migrates  to  the  upper  side,  so 
that  both  eyes  come  to  lie  on  the  same  side  of  the  body. 
The  mouth  also  tends  to  become  unsymmetrical.  The 
flatfish,  .consequently,  illustrates  well  the  principles  of  self- 
adaptation  to  a  peculiar  environment. 

The  catfishes  are  distinguished  by  the  possession  of 
four  to  eight  long  barbels  around  the  mouth,  and  by  the 


240 


ZOOLOGY 


absence  of  scales  on  the  body.  They  are  characteristic  of 
South  America,  but  there  are  a  large  number  of  species  in 
the  United  States,  mostly  found  in  the  Mississippi  valley 


EVS 

\  v\ 


FIG.  222.  —  One  of  the  flatfishes,  seen  from  the  upper  side.    Two-thirds  nat. 
size.    Photo,  by  W.  H.  C.  P. 


and  the  Great  Lakes,  inhabiting  deep  or  sluggish  waters, 
and    living    in    the    mud.      The    common    New    England 


FIG.  223.  —  Ameiurus  nebulosus,  the  catfish.    About  one-half  nat.  size.   Photo, 
of  living  animal  by  Dr.  R.  W.  Shufeldt,  "  Bull.  U.  S.  Fish  Com.,"  1899. 


THE  KNELT  ANT)   ITS  ALLIES  241 

species  is  Ameiurus1  catus?  the  bull-head  or  horn-pout.3 
It  was  with  reference  to  this  species  that  Thoreau  wrote 
that  they  are  "a  bloodthirsty  and  bullying  race  of  rangers, 
inhabiting  the  river-bottoms,  with  ever  a  lance  at  rest  and 
ready  to  do  battle  with  their  nearest  neighbor."  The 
stiff,  jagged  rays  of  the  pectoral  fins  can  make  severe 
wounds.  The  great  catfish  of  the  Mississippi  River, 
which  may  weigh  up  to  90  kilogrammes,  is  known  as 
Ameiurus  lacustris.^  This,  as  well  as  most  other  species 
of  catfish,  is  much  prized  as  food. 


FIG.  224.  —The  brook  sucker.     After  Goode. 

The  suckers  are  characteristic  North  American  fish, 
abundant  in  every  creek,  and  consequently  known  to  every 
lover  of  woods  and  brooks.  Characteristic  is  the  form  of 
lips,  which  are  thick  and  drawn  down  at  the  corners.5  They 
are  rather  sluggish  fishes,  and  feed  on  small  aquatic  insects 
and  suck  up  mud.  They  are  not  generally  esteemed  as 
food,  inasmuch  as  their  flesh  is  coarse  and  very  full  of 
bones.  In  the  Mississippi  valley,  however,  they  are  so 
abundant  and  large  that  they  are  of  some  commercial 
importance. 

,  not  curtailed.  2  Cat.  8  Fig.  223. 

4  Living  in  lakes.  5  Fig.  224. 

R 


242  ZOOLOGY 

The  term  "minnow"  is  applied  to  two  distinct  families  of 
small  fish.  One  of  these  is  also  known  as  "  killifish."  The 
killifish  have  a  broad  head  covered  with  scales,  and  have 
well-developed  teeth  in  the  mouth.  They  occur  in  schools 
in  shallow  water  on  the  shore,  and  ascend  streams  to  their 
source.  They  are  carnivorous,  and  feed  at  the  surface. 
In  one  species  from  the  Southern  coast,  Heterandria  1  for- 
niosaf  the  male  is  only  about  two  centimetres  long,  and  is 
the  smallest  known  vertebrate.  Our  commonest  species  on 


FIG.  225.  —  Fundulus  heteroclitus,  a  killifish  or  shore  minnow.     Nat.  size. 
Photo,  by  W.  H.  C.  P. 


the  shore,  or  in  brackish  water,  is  Fundulus  3  heteroclitus  4 
(Fig.  225).  The  minnows  of  the  other  family  have  a  nar- 
row head  without  scales,  and  with  no  teeth  in  the  mouth. 
They  occur  exclusively  in  fresh  water,  and  are  known  as 
"shiners.'''  The  "goldfish"  is  related  to  this  group. 

The  pike  and  pickerel  (Esox5)  are  roughly  cylindrical 
fishes,  with  large  mouth,  elongated,  depressed  jaws,  and 
strong,  hooked  teeth.6  They  are  large,  voracious,  fresh- 
water fishes,  confined,  with  the  exception  of  a  single  species, 
to  the  United  States.  The  "  muskallunge  "  of  the  Great 


s,  different  ;  dnfa,  dj>fy>6s,  man,  male.  2  Comely. 

3  fundus,  bottom.  4  ere^/cXi-ros,  irregular  or  unusual. 

5  fool-,  a  fish  living  in  the  Rhine,  mentioned  by  Pliny. 

6  Fig.  226. 


THE  SMELT  ANT)   ITS  ALLIES 


243 


Lakes  reaches  a  length  of  two  metres.  It  is,  fortunately, 
somewhat  rare,  otherwise  there  would  be  few  other  in- 
habitants of  our  large  streams. 


FIG.  22(>.  —  Lucius  luci'tis,  the  pike.     About  one-fifth  nat.  size.     Photo,  of 
living  animal  by  Dr.  R.  W.  Shufeldt,  "  Bull.  U.  S.  Fish  Com.,"  1899. 

The  shad  is  a  representative  of  a  family  —  the  herring 
family — which  has  played  an  important  part  in  the  civiliza- 
tion of  Europe.  There  is  an  old  adage  in  Holland  to  the 


FIG.  227.  — Alosa  sapidissima,  the  shad.     After  Goode. 

effect  that  Amsterdam  is  built  on  herring-bones  ;  and  the 
Emperor  Charles  V.  said  that  the  herring  brought  greater 
wealth  to  'the  Netherlands  than  did  America  to  Spain. 
Our  common  shad,  Alosa l  sapidissima,2  ranges  from  New- 

1  From  Saxon  allis,  old  name  of  the  European  shad. 

2  Most  delicious. 


244  ZOOLOGY 

foundland  to  Florida.1  Next  to  the  Pacific  salmon  and 
cod,  it  is  commercially  our  most  important  fish,  for  the 
catch  of  Atlantic  shad  for  1896  exceeded  one  and  a  half 
million  dollars.  The  Pacific  coast  has  been  successfully 
stocked  with  shad  from  the  Atlantic.  The  Atlantic  shad, 
like  the  salmon,  migrate  up  streams  to  deposit  their  eggs. 
The  alewives  have  the  same  habit.  The  herring,  on  the 
contrary,  spawn  in  the  sea.  As  the  common  name,  allied 
to  the  German  Heer,  an  army,  implies,  they  travel  in  great 
schools.  The  menhaden,  which  also  occur  in  great  schools, 
have  of  late  years  been  destroyed  in  vast  numbers  to  make 
fertilizers. 

The  eels  are  easily  distinguished  by  their  serpentine 
form,  the  absence  of  ventral  fins,  the  long  dorsal  fin,  and 
the  rudimentary  or  absent  scales.  These  fish  occur  all 
along  our  coast  and  ascend  streams.  During  the  day  they 
lie  hidden  in  mud  and  at  night  they  feed,  their  principal 
prey  being  small  aquatic  animals,  the  young  of  other  fish, 
and  shrimps  and  crayfishes  during  the  moulting  period. 
On  account  of  the  narrowness  of  the  gill-opening,  they 
may  live  for  some  time  out  of  water  in  a  moist  place.  The 
reproduction  of  the  eel  was  long  a  mystery.  All  sorts  of 
creatures  have  in  past  times  been  supposed  to  produce 
them,  ranging  from  the  gods  to  water-beetles.  They  have 
even  been  thought  to  be  generated  from  slime.  We  now 
know,  however,  that  there  are  both  male  and  female  indi- 
viduals ;  that  the  males  live  chiefly,  but  not  exclusively,  in 
the  sea ;  that  reproduction  occurs  chiefly  in  the  sea ;  and 
that  the  young  females  come  from  the  sea  and  pass  up  the 
rivers  during  the  spring. 

The  pipe-fishes  and  their  allies  (Lophobraiichii)  include 

iFi.  227. 


THE  SMELT  AND  ITS  ALLIES 


245 


a  number  of  aberrant  forms.  Some  of  these  are  greatly 
elongated,  like  the  pipe-fish  proper  (Fig.  228)  ;  others  are 
shorter  and  stouter,  like  the  "  sea-horse."  All  have  an 


FIG.  228.  —  Siphostomafuscwn,  the  pipe-fish.   Nat.  size.    Photo,  by  W.  H.  C.  P. 

elongated  snout,  and  usually  a  long,  slender  tail.  The 
body  is  encased  in  bony  plates,  and  the  male  is  often  pro- 
vided with  a  brood-pouch,  in  which  the  developing  young 
are  carried. 

Besides  the  bony  fishes,  which  we  have  just  considered 
in  detail,  there  are  various  other  classes  of  fish. 


FIG.  229.  — Petromyzon,  the  lamprey.    One-fourth  nat.  size.     After  Goode. 

The  Cyclostomi,  or  lamprey  eels,  are  the  only  parasitic 
vertebrates.     In  the  adult  stage  they  either  live  attached 


246 


ZOOLOGY 


to  the  outside  of  other  fishes,  sucking  their  blood,  or  else 

they  may  penetrate  into 
the  body  cavity.  They 
do  not  bite,  because  they 
have  110  lower  jaw,  and 
are  known  as  "  round- 
mouthed"  eels.1  Lam- 
preys are  found  in  the  seas 
and  in  the  rivers  of  the 
temperate  zones.  They 
occur  on  our  Eastern 
coast  and  ascend  rivers ; 
others  live  in  the  lakes  of 
New  York,  in  the  Great 
Lakes,  and  in  the  Missis- 
sippi valley.  In  Europe 
£  >  they  are  much  esteemed 
as  food. 

The  Selachians  include 
the  sharks  and  rays,  all 
inhabitants,  of  the  sea. 
They  may  be  distin- 
guished from  the  bony 
fishes  by  the  rough  skin, 
beset  with  spines,  and  by 
the  cartilaginous  skele- 
ton. We  have  a  num- 
ber of  sharks  on  our 
Northeastern  coast,  of 
which  the  dogfishes  and 
the  sand-shark  are  the 

i  Fig.  229. 


lill 


THE  SMELT  AND  ITS  ALLIES  247 

commonest  (Fig.  230).  They  are  all  carnivorous  animals 
and  powerful  swimmers.  They  feed  on  the  larger  Crus- 
tacea and  fish. 

The  living  Ganoidei  are  a  remnant  of  a  very  extensive 
group  which  existed  in  geological  times.  North  America 
is  especially  rich  in  existing  representatives  of  this  group, 
as  of  several  other  old  groups,  such  as  the  turtles,  tailed 
amphibians,  and  the  king-crab.  Of  the  five  families  of 
ganoids,  fonr  are  represented  in  this  country.  In  the 
following  four  paragraphs  we  shall  consider  a  type  of  each 
of  the  native  families. 

The  sturgeons  have  five  rows  of  bony  scales  on  the 
trunk  and  four  barbels  on  the  head.1  They  occur  both 


FIG.  231.  —  Acipenser,  the  sturgeon.     One-sixteenth  nat.  size.    After  Goode. 

in  the  sea  and  in  the  Great  Lakes  and  the  rivers  of  the 
Central  States.  Although  of  large  size,  they  feed  for  the 
most  part  on  small  aquatic  animals,  such  as  worms,  insect 
larvae,  and  small  fish.  The  flesh  of  some  species  is  much 
used  as  food  ;  the  eggs  taken  from  the  ovaries  (roe)  con- 
stitute a  delicacy  known  as  "caviare." 

The  spoonbill,  Avhich  has  an  elongated,  flattened  snout 
and  is  almost  without  scales,  is  a  large  fish  found  in 
the  Mississippi  River.  It  is  also  called  "paddle-fish"  or 
"  duck-bill  catfish."  It  becomes  two  metres  long  and  seeks 
small  animals  in  the  mud,  which  it  stirs  up  with  its  snout. 

1  Fig.  231. 


248 


ZOOLOGY 


The  garpikes  are  known  by  their  long  snout  (Fig  232). 
They  are  completely  clad  in  an  enamel  coat  of  mail.  They 
are  of  sluggish  habits,  but  voracious,  and  their  flesh  is 


FIG.  232.  — Lepidosteus,  the  garpike.     One-eighth  iiat.  size.     After  Tenney. 

valueless  as  food.     One  species  is   found   in   China,  the 
others  in  the  rivers  of  North  America. 

The  bowfin  (Amia1)  occurs  in  the  rivers  and  lakes  of 
the  United  States.     It  has  a  short  body,  a  blunt  head,  and 


FIG.  233.  —  Amia  calva,  the  bowfin.    One-sixth  nat.  size.    From  Leunis. 

a  long,  dorsal  fin  (Fig.  233).  It  is  the  sole  survivor  of  a 
formerly  large  family. 

The  Dipnoi 2  include  only  three  rare  foreign  forms,  which 
seem  to  form  a  transition  between  fishes  and  the  higher 
groups,  for  some  of  them  have  lungs  in  addition  to  gills. 
From  some  such  lunged  fishes  must  the  amphibia  have 
arisen  (Fig.  234). 

Ancestry  of  Vertebrates.  —  The  fishes,  amphibia,  reptiles, 
birds,  and  mammals,  which  are  considered  in  this  and  the 
following  chapters,  constitute  together  the  group  of  verte- 
brata,  or  backboned  animals.  All  the  animals  treated  of 


,  ancient  name  of  a  fish. 


2  5£s,  twice  ;  TTVOT?,  breath. 


TILE  SMELT  AND  ITS  ALLIES 


249 


250 


ZOOLOGY 


FIG.  236.  —  Ciona,  a  simple 
tunicate,  o,  mouth  ;  at,  open- 
ing of  atrium,  or  exhalant 
opening;  st,  stolon.  After 
Leuckart  and  Nitche's  dia- 
grams. 


FIG.  238.  —  Balanoglossus,  the  acorn- 
tongued  worm.  The  proboscis  at  the 
anterior  end  is  at  the  top  of  the  figure 
(partly  outside)  ;  behind  it  is  an 
orange-colored  collar ;  then  follows 
the  long,  brown-red  trunk.  Nat.  size. 
Photo,  of  living  animal  by  W.  H.  C.  P. 


FIG.  237.  —  Botryllus,  a  compound  tunicate.    Nat.  size.    Photo,  by  W.  H.  C.  P. 


THE  SMELT  AND  ITS  ALLIES  251 

in  earlier  chapters  are  invertebrates.  Between  verte- 
brates and  invertebrates  and  connecting  the  fishes  with 
more  worm-like  ancestors,  is  the  lancelet  or  Amphioxus.1 
This  slender,  rod-like  animal  is  only  50  to  70  milli- 
metres long.  Its  internal  structure  shows  its  relationship 
with  vertebrates  ;  it  has  the  forerunner  of  a  vertebral 
column  and  a  spiral  nerve  and  it  has  also  gill  slits  like  a 
fish,  but  it  has  no  skeleton.2  It  lives  in  sandy  seashores 
in  temperate  and  tropical  zones.  On  our  Eastern  coast  it 
is  found  from  Chesapeake  Bay  south.  It  stands  embedded 
in  the  sand,  the  tentacle-fringed  mouth  projecting  above 
the  surface.  It  feeds  on  minute  organisms  of  all  sorts. 

Of  the  invertebrate  groups,  that  of  Tunicata  lies  nearest 
to  the  stem  from  which  the  vertebrates  arose.  The  adult 
animals,  however,  are  very  different  from  vertebrates,  for 
they  are  attached  (Fig-  236),  and  sometimes  even  form 
colonies  (Fig.  237).  But  the  young  animals  are  much 
like  tadpoles  of  frogs  ;  not  merely  superficially,  but  in 
their  structure.  Going  further  back  it  seems  clear  that 
vertebrates  have  developed  out  of  the  worms.  A  very 
worm-like  animal,  which  seems  to  foreshadow  the  verte- 
brates in  having  gill  slits  and  the  forerunner  of  a  back- 
bone, is  common  in  our  sandy  beaches.  This  is  Balano- 
glossus3  —  the  acorn-tongued  worm,  so  called  from  the 
shape  of  its  proboscis  (Fig.  238). 

1  a/j.<t>i,  both  [ends]  ;  6£tfs,  sharp  pointed. 

2  Fig.  235.  3  pdXavos,  acorn  ;  7\w<7(ra,  tongue. 


252 


ZOOLOGY 


APPENDIX   TO   CHAPTER  XVI 

KEY    TO    THE    PRINCIPAL    ORDERS    OF    FISHES 

«i.     Without  skull,  paired  fins,  or  heart ;  blood  color- 
less   Acrania 

(Ex.  Amphioxus) 

ao.     With  skull,  heart,  and  red  blood  [Craniota]. 
61.     Without  lower  jaw  or  paired  fins 


62-     With  lower  jaw  and  paired  fins  [Gnatho- 

stomi]. 
Ci.     Intestine  with  spiral  valve. 

d\.     Without  an   operculum  covering 
the  gill  openings  ;  scales  toothed 

$>.     Operculate  ;  skin  with  enamelled 

scales. 

e\.     Breathing  by  means  of  gills 
only   .         .         .         .         . 

eg.     Breathing  by  both  gills  and 
a  lung         .''-   -, ...•        .    .   • . 

eg.     Intestine  without  spiral  valve  ;  skele- 
ton bony  .         .         .         .        .'.'.' 


Cyclostomi 

(Lamprey  eels) 


Selachii 

(Sharks  and  rays) 


Ganoidei 

(Ganoid  fishes) 
Dipnoi 

(Mud  fishes) 

Teleostei 

(Bony  Fishes) 


KEY   "TO    THE    SIX    SUBORDERS    OF    TELEOSTEI 

Gills  comb-like. 

b\.     Intermaxillaries  and   maxillaries   movable 

on  each  other. 
Ci.     Dorsal   fin,  anal   fin,  and  ventral  fin 

spinous  anteriorly. 

d\.     Pharyngeal  bones  distinct    .         .         Acanthopteri 
(Perches,  darters,  sunfishes,  toadfishes,  sculpins,  silversides, 
sticklebacks) 

d2.     Pharyngeal  bones  united      .        .  Pharyngognathi 
c2.     Dorsal,  anal,  and  ventral  fins  without 
spines. 


APPENDIX  TO   CHAPTER  XVI  253 

d\.  Ventral  fin,  when  present,  placed 
on  throat  or  breast ;  air-bladder 
without  air  tube  .  .  .  Anacanthini 

(Codfishes,  flatfishes) 

do.  Ventral  fin,  when  present,  placed 
ventrally  ;  air-bladder  with  air- 
tube  Physostomi 

(Smelt,  trouts,  whitefishes,  catfishes,  .suckers,  minnows, 
shads,  eels) 

&2.     Intermaxillaries  and  maxillaries  united  with 

each  other  and  with  skull         .        .         .         Plectognathi 
Gills  small,  tuft-like ;  body  covered  with  bony 
plates       ........      Lophobranchii 

(Pipe-fishes) 


CHAPTER   XVII 

THE   NEWT   AND   ITS   ALLIES 

THE  newts  belong  to  the  class  Amphibia,1  or,  as  it  is 
also  called,  Batrachia,  characterized  by  the  fact  that,  while 
they  have  no  rayed  fins  like  fishes,  but  legs  instead,  they 
have  functional  gills  during  at  least  a  part  of  their  free 
life.  The  eggs,  which  are  laid  in  water,  are  without  a 
hard  shell. 

The  little  newt  Diemyctylus  virldescens 2  is  found  in 
New  England  and  westward  to  the  Mississippi  valley. 
During  different  stages  of  development  it  assumes  widely 
different  habits.  The  eggs  are  laid  during  the  spring  in 
water,  where  they  hatch  after  three  to  five  weeks  and 
appear  as  olive-colored  tadpoles  with  external  gills.  At 
this  time  they  have  an  exclusively  animal  diet,  feeding  on 
minute  Crustacea,  larval  insects,  snails,  and  aquatic  worms. 
In  August  the  gills  and  tail-fill  become  absorbed,  and  the 
transformed  animal  takes  to  land  and  lives  under  stones 
at  some  distance,  it  may  be,  from  water.  At  this  time  it 
has  a  vermilion  color,3  and  feeds  on  spiders,  insects,  and 
earthworms.  After  two  or  three  years  the  newt  assumes  a 

1  Keys  to  the  Orders  of  Amphibia  and  to  the  families  of  Urodela  will 
be  found  in  the  Appendix  to  this  Chapter,  page  266. 

2  The  newt  of  the  Pacific  coast  is  D.  torosus. 

8  The  color  and  habitat  of  the  terrestrial  young  Diemyctylus  are  so 
different  from  the  fully  matured  aquatic  form  that  the  two  were  formerly 
regarded  as  distinct  species. 

254 


THE  NEWT  AND  ITS  ALLIES  255 

brown  color,  and  eventually  the  olive-green  or  viridescent 
color  of  the  adult.  It  then  takes  to  the  water  and  is 
found  especially  in  springs,  and  in  ponds  and  brooks  fed 
by  springs.  It  now  subsists  on  various  aquatic  worms, 
crustaceans,  insects,  and  mollusks.  The  newt  gains  oxygen 
for  respiration  by  swallowing  air  mixed  with  water.1 

Distribution. — The  Amphibia  live  chiefly  in  tropical  and 
subtropical  countries,  although  a  number  of  them  belong 
to  the  colder  parts  of  the  temperate  zone.  There  are  no 
strictly  polar  species,  although  one  species  of  frog  extends 
from  Massachusetts  north  to  Alaska.  The  Gymnophiona2 
are  confined  to  tropical  countries  and  are  most  abundant 
in  South  America.  They  live,  like  earthworms,  in  the 
ground  and  have  more  or  less  rudimentary  eyes.  The 
Urodela  are  confined  in  their  distribution  to  the  Northern 
Hemisphere  (excepting  that  two  or  three  species  extend 
along  the  Andes  south  of  the  equator).  North  America 
is  especially  rich,  both  in  species  and  individuals,  of  Uro- 
dela. The  Anura,  or  toads  and  frogs,  are  found  in  all  parts 
of  the  world,  especially  in  South  America  and  Australia. 

Families  of  Urodela.  —  Of  the  American  Urodela,3  the 
Sirenidae  include  the  Siren,4  or  mud-eel,  of  the  Southern 
States.  This  species  becomes  60  centimetres  long,  and  is 
of  a  dark  lead  color  (Fig.  239).  It  is  needlessly  feared 
by  the  negro  rice  cultivators,  who  slaughter  it  in  great 
numbers. 


1  Newts  may  be  captured  by  sweeping  with  a  net  the  muddy  bottoms 
of  small,  spring-fed  pools.     They  can  be  kept  for  months  in  an  aquarium, 
where  they  should  be  fed   thrice  a  week  with   earthworms  or  freshly 
chopped  beef. 

2  From  yv/mv6s,  naked  ;  60iW,  a  fabulous,  snake-like  animal. 

3  ou/sd,  tail ;  SiJXos,  conspicuous.  4  A  mythological  creature. 


256 


ZOOLOGY 


THE  NEWT  ANT)  ITS  ALLIES  257 

The  Proteidae  l  include  our  Necturus,  commonly  known 
as  mud-puppy  or  water-dog,  which  is  found  from  the 
Hudson  River  to  the  Mississippi  valley,  and  is  very 
abundant  in  the  Great  Lakes.  Its  external  gills  are 
very  large,  and  red  with  the  blood  flowing  in  them.  It 
feeds  011  small  water-animals.  In  April  or  May  it  lays 
eggs  about  the  size  of  a  pea.  A  curiously  modified  form 
of  Necturus  occurs  in  caves  (Fig.  240).  Another  member 
of  this  family  is  the  cave  "  olm  "  of  western  Austria. 

The  Amphiumidae2  include  only  the  Congo  snake  of 
the  Carolinas  and  Gulf  States.  This  black,  snake-like 
Urodelian  is  about  a  metre  long,  and  lives  in  bayous  and 
muddy  ditches  (Fig.  241).  It  has  the  entirely  undeserved 
reputation  of  being  injurious. 

The  Cryptobranchidae 3  include  the  so-called  "hell- 
bender" of  the  Ohio  valley  and  south.4  It  is  a  very 
voracious  scavenger  of  the  water,  and  bites  the  hook 
fiercely.  It  is  noted  for  its  great  tenacity  of  life  under 
unfavorable  conditions.  The  only  other  living  repre- 
sentative of  this  family  is  the  Japanese  giant  salamander, 
which  becomes  three  metres  long. 

The  Amblystomidae 5  include  some  twenty-five  species 
belonging  to  five  genera,  four  of  which  occur  in  northern 
and  eastern  Asia,  and  the  fifth,  Amblystorna,  is  confined 
to  the  United  States  and  Mexico,  excepting  one  species, 
occurring  in  Siam.  The  common  species  of  New  England 
and  the  Central  States  is  known  as  the  Spotted  Sala- 

1  IIpoTerfs,  a  sea-god  possessed  of  the  power  of  changing  himself  into 
different  shapes. 

2  Probably  a  modification  of  a  native  name. 

3  /cpu7rr6s,  hidden  ;  ppdyxiOV>  gill- 

4  Fig.  242.  5  From  d/ijSXtfs,  blunt ;  <rr6^a,  mouth. 

s 


258 


ZOOLOGY 


mander.     It  is  about  15  centimetres  long,  and  black,  with 
a  series  of  yellow  spots  on  each  side  of  the  back.     It  lays 


FIG.  242.  —  Cryptobranchus,  the  "  hellbender."     Reduced.     From  "  Stand- 
ard Natural  History." 


eggs   in  springs  or  ponds   during  April ;   the  dark   gray 
eggs  are   contained  in   great   masses   of  jelly  which   are 


FIG.  243.  —  The  larva  of  Amblyttoma  tiyritmm,  the  Axolotl  stage  of  the  tiger 
salamander.    FromMivart. 


THE  NEWT  AND  ITS  ALLIES  259 

attached  to  sticks  at  or  near  the  surface  of  the  water. 
The  larvae  of  the  more  southern  species  often  reach  a  size 
considerably  larger  than  the  adult,  and  breed  before  the 
gills  are  absorbed.  In  a  Mexican  species  the  larval 
state  is  never  transcended.  The  larva  of  Amblystoma 
(Fig.  243)  was  formerly  described,  indeed,  as  a  distinct 
species. 

The  Plethodontidae  *  and  Desmognathidae  2  include  a  num- 
ber of  small  Urodeles,  having  a  close  general  resemblance 


FIG.  244.  —  Plethodon,  the  red-backed  salamander.     Slightly  reduced.  Photo, 
of  living  animal  resting  on  a  leaf. 

and  similar  habits.  Plethodon,  of  the  eastern  United 
States,  is  lead-colored  above,  very  often  with  a  broad, 
red  dorsal  band  (Fig.  244).  It  is  found  under  logs, 
and  is  very  active.  Spelerpes3  is  lemon-yellow  and  white 
below,  and  Desmognathus  is  brown  above,  with  gray  or 

,  abundance  ;  (55otfs,  (556iros,  tooth.  2  5eo>6s,  bond  ;  yvd6os, 

jaw.         3  trTT^Xcuoj',  cavern  ;  fyirTjs,  a  crawler. 


260  ZOOLOGY 

purplish  spots  on  the  sides.  Both  Spelerpes  and  Desmo- 
gnathus  live  in  and  about  running  brooks,  under  stones 
and  fallen  logs.  Their  eggs  are  attached  to  the  under 
surface  of  submerged  stones.  The  adults  are  easy  to  keep 
in  confinement  in  a  moist  fernery.  They  may  be  obtained 
out  of  doors  all  the  year  round,  excepting  during  the  time  of 
deep  snow.  There  are  four  species  of  Spelerpes  and  three 
species  of  Desmognathus  in  the  northern  United  States. 

Metamorphosis.  —  As  we  have  seen,  all  Amphibia  have 
gills  while  young,  but  some  lose  them  before  maturity 
while  others  retain  them  permanently.  Those  species 
which  retain  the  gills  pass  their  whole  life  in  water  ;  the 
others  may  live  on  the  land.  The  loss  of  gills  is  asso- 
ciated with  the  assumption  of  a  land  life.  In  the  Ambly- 
stoma  we  have  species  which  are  curiously  intermediate 
between  the  two  classes  in  that  they  may  retain  their 
gills,  tail-fins,  and  other  structures  adapted  to  aquatic  life,1 
even  to  the  time  of  reproduction  ;  or  they  may  lose  their 
gills  and  tail-fins.  The  first  result  follows  if  they  are  pre- 
vented from  coming  on  land ;  the  second,  if  they  are  forced 
to  leave  the  water.  The  capacity  of  the  Mexican  Axolotl 
for  either  becoming  an  adult  or  remaining  a  larva  was 
first  shown  by  some  experiments  of  the  German  naturalist 
Weismann  and  a  pupil  of  his.  It  will  be  seen  that  when 
forced  to  live  in  the  water  Axolotl  retains  permanently 
a  larval  condition  ;  and  one  would  never  know  that  in  this 
larval  condition  the  animal  is  not  adult  were  it  not  for  the 
accident  of  its  sometimes  becoming  adult.  It  is  quite 
possible  that  all  of  the  Urodela  which  retain  their  gills 
throughout  life  may  formerly  have  had  a  gill-less  adult 
stage  which  is  now  lost. 

1  Compare  Fig.  243. 


THE  NEWT  AND  ITS  ALLIES 


261 


Early  Development  of  Urodela.  —  The  eggs  of  Urodela 
are  deposited  in  a  gelatinous  mass  in  water,  and  are 
attached  to  submerged  plants,  or  to  other  objects  in  the 


FIG.  12  FIG.  13.  FIG.  17.  FIG.  18.  FIG.  19. 

FIG.  245.  —  Developmental  stages  of  Spelerpes  bilinecitus.  Figx.  S-'J,  neural 
groove  beginning  to  form;  Figs.  10,  11,  neural  groove  closed;  Figs.  12,  i;>, 
head  beginning  to  form;  Figx.  14-lf>,  tail  formed,  yolk  absorbing;  Fig.  17, 
embryo  capable  of  moving  in  egg  membrane ;  Fig.  IS,  embryo  just  able  to 
swim  ;  Fig.  W,  three  days  after  hatching.  The  letters  indicate  the  successive 
stages.  After  H.  H.  Wilder,  from  "The  American  Naturalist." 

water,  either  singly  or  in  masses,  according  to  the  species. 
The  eggs  contain  much  yolk ;  consequently  the  cleavage  is 
partial,  and  the  embryo  seems  to  develop  on  a  small  part 


262 


ZOOLOGY 


only  of  the  yolk  and  for  some  time  after  hatching  the  yolk 
mass  hangs  as  a  lump  on  the  under  side  of  the  embryo. 
Very  early  a  deep  groove,  bounded  by  a  pair  of  folds, 
arises  on  the  edge.  This  groove  is  large  in  front  (Fig. 
245,  &).  It  forms  the  beginning  of  the  brain  and  spinal  cord. 
The  feathery  gills  and  the  beginnings  of  the  appendages 


FIG.  246.  —  Pipa  americana.    Female  with  young  in  pits  on  its  back. 

next  sprout  out,  while  the  trunk  continues  to  elongate  and 
assume  the  form  of  a  young  salamander  (Fig.  245). 

Families  of  Anura.  —  Of  the  Anura  there  are  eight  or 
ten  times  as  many  species  as  there  are  of  the  Urodela. 
They  are  distributed  into  nearly  a  score  of  families.  Of 


THE  NEWT  AND  ITS  ALLIES 


263 


these  a  few  of  the   more  interesting  deserve  to  be  men- 
tioned. 


FIG.  247.  —  Section  through  skin  of  back  of  Pip  a,  americana,  showing  develop- 
ing embryos.     Much  enlarged. 

The  Pipidae  include  the  South  American  Pipa,  note- 
worthy because  of  the  habit  which  the  female  has  of 
brooding  its  young  in  pits  of  the  skin  on  her  back 
(Figs.  246,  247). 


FIG.  248.  —  Nodelphys,  brooding  tree-frog,  female,  from  Venezuela.  In  the 
hinder  part  of  the  trunk  the  opening  to  the  brood-pouch  is  seen.  From  a  water- 
color  painting  at  the  Museum  of  Comparative  Zoology  at  Harvard  College. 

The    Hylidae,    or    tree-toads,    include    various    arboreal 
species  in  which  the  ends  of  the  fingers  are  modified  for 


264 


ZOOLOGY 


holding  on  to  objects  by  suction.  Of  these  there  are  over 
one  hundred  and  seventy  species,  especially  abundant 
in  tropical  America.  In  one  member  of  this  family  the 
female  has  a  pouch  on  the  back,  opening  in  the  hinder 
third  of  the  trunk  (Fig.  248).  In  this  the  young  are 


FIG.  249.  —  Bufo  lentiginosus,  the  American  toad.     Photo,  of  living  animal, 
resting  on  the  ground,  by  W.  H.  C.  P. 


brooded.  The  most  common  tree-toad  of  the  northern 
United  States  extends  from  Canada  to  Florida,  and  west 
to  Kansas.  It  is  variable  in  color,  being  green  or  brown, 
according  to  the  color  of  the  background,  leaf,  or  bark, 
on  which  it  is  resting.  It  has  a  loud,  coarse  trill,  often 


THE  NEWT  AND  ITS  ALLIES  265 

erroneously  regarded  as  a  weather  sign.      The  eggs  are 
laid  in  small  bunches  in  shallow  water. 

The  Bufonidae  include  the  common  toads  which  occur 
all  over  the  world.  Our  Eastern  toad1  inhabits  nearly  all 
the  United  States  east  of  the  Rocky  Mountains.2  It  is 
crepuscular  in  its  habits,  and  feeds  chiefly  on  insects  and 
worms.  The  eggs  are  deposited  in  two  long,  parallel 
strings  of  albumen,  which  lie  coiled  at  the  bottoms  of* 


FIG.  250.  —  Rana  damttano,  green  frog.    Nat.  size.    Photo,  of  living  animal 

by  W.  H.  C.  P. 

ponds,  hatch  out  in    May,    and    metamorphose    about   a 
month  later. 

The  Ranidae  are  almost  confined  to  the  Northern  Hemi- 
sphere and  the  East  Indies.  In  the  northern  United  States 
there  are  some  eight  species,  of  which  the  commonest  are: 
the  leopard-frog,  of  green  color,  with  irregular  black 
blotches  edged  with  whitish  ;  the  pickerel-frog,  light 
brown,  with  two  rows  of  oblong  square  brown  blotches 

1  Bufo  lentiginosns.  2  Fig.  249. 


266  ZOOLOGY 

on  the  back  ;  the  wood-frog,  living  in  damp  woods,  pale 
reddish  brown,  with  a  brown  band  on  the  side  of  the  head ; 
the  green  frog,  of  uniform  bright  green  to  brown  color, 
with  numerous  small  dark  spots,  and  with  glandular  folds 
(Fig.  250)  ;  and  the  bull-frog,  of  great  size,  green,  with 
small  faint  spots  011  the  back. 


APPENDIX   TO   CHAPTER   XVII 

KEY  TO  THE  ORDERS  OF  AMPHIBIA 

a\.   Appendages  and  tail  lacking;  body  worm-like ; 

skin  furrowed  transversely       „     •.''-.         .        Gymnopliiona 
«2-    Appendages  present. 

61.  Body  elongated ;  tail  present ;  generally  4, 
but  rarely  only  the  2  anterior  appendages 
present  ...  .  _  „  '  .,  ..  .  ^  Urodela 

b2-   Body  short ;  in  adult  condition  tailless        .  -  Anura 

KEY  TO  THE  FAMILIES  OF  URODELA 

a\.    External  gills  persistent  throughout  life  ;  maxil- 
lary bone  small  or  wanting. 
61.    Body  eel-like  ;  hind  legs  absent ;  jaws  with 

horny  sheath    .         .        .         .        .        ..  Sirenidm 

b2.    Body  salamander-like  ;  hind  limbs  present ; 

teeth  on  jaws    .       _'*,  •   •  '  -*        .      ....  Proteidcv 

a2.    External  gills  normally  disappearing  in  adult ; 

limbs  4  ;  maxillaries  present. 
61.    Side  of  neck  with  spiracular  opening  ;    no 

eyelids, 
ci.    Limbs  rudimentary      ..        .  .        AmphiumidcR 

c2.    Limbs  well  developed  .         .  .  Cryptobmnchidce 

60.  Side  of  neck  without  spiracular  opening  in 
adult ;  eyelids  present. 


APPENDIX  TO   CHAPTER  XVII 


267 


Palatine  teeth  in  transverse  (or  nearly 

transverse)  series. 
d\.    Vertebrae  doubly  concave. 

e\.    Parasphenoid  without  teeth  ; 

tongue  large  ;  toes  4-5 
63.    Parasphenoid     with     teeth ; 

tongue  small      .. 
do.    Vertebrae    convex    behind    only ; 

tongue  moderate  ;  toes  5 
Palatine  teeth  in  2  longitudinal  series, 
diverging  behind        . 


Amblystomidce 

PlethodontidcK 

Desmognathidce 

Pleurodelidat 

(Ex.  Diemyctylus) 


CHAPTER   XVIII 

THE   LIZARD   AND   ITS   ALLIES 

THE  lizards  belong  to  the  class  of  Reptiles,1  which  are 
vertebrates  in  whose  skin  horny  or  bony  scales  or  plates 
are  formed.  They  constantly  breathe  by  means  of  lungs, 
and  lay  large  eggs  provided  with  a  tough  leathery  or 
calcareous  shell. 

The  Sauria,  or  lizards,  constitute  a  large  order  charac- 
teristic of  the  tropical  and  subtropical  countries  and 
reaching  the  maximum  of  its  development  in  South 
America,  while  in  the  northern  continents  it  is  relatively 
poorly  represented.  Lizards  are,  as  a  rule,  carnivorous, 
and  since  they  destroy  insects  injurious  to  vegetation,  they 
may  be  counted  as  beneficial  to  man. 

Anolis  2  is  one  of  the  family  Iguanidae,3  a  large  group  of 
lizards  characteristic  of  the  Western  Hemisphere.  The 
family  is  known  by  the  thick  tongue,  by  a  large  scale 
in  the  middle  of  the  head  in  front  of  the  eyes,  and  by  the 
fact  that  all  four  legs  are  well  developed.  The  genus 
Anolis  contains  eighty  tropical  species.  Oar  species  lives 
in  pine  woods  from  the  latitude  of  Tennessee  south  to  the 
Gulf  and  the  island  of  Cuba.  Its  graceful  form  and  bright 
colors  make  it  one  of  the  most  beautiful  of  lizards.  It 

1  A  key  to  the  four  orders  of  Reptiles  will  be  found  in  the  Appendix  to 
this  Chapter,  page  280. 

2  Anoli,  native  name.  3  Native  name. 

268 


THE  LIZAUI)  AND  ITS  ALLIES  269 

lives  on  trees,  eats  insects,  is  not  timid,  can  live  well  in 
confinement,  and,  like  the  chameleon  of  Europe,  has  the 
power  of  changing  its  colors  from  bright  green  to  dirty 
brown.  Besides  Anolis  we  have  various  other  lizards  of 
the  family  Iguanidse.  The  horned  toad  of  the  Southwest, 
Avhich  has  a  broad,  flattened  body  and  long  spines  on  the 
head,  and  lives  in  dry,  sandy  places,  is  a  familiar  object.1 
In  the  South  Central  and  Southern  States  lives  the  elon- 
gate "  swift "  of  varying  color,  often  with  black,  irregular 


FIG.  251.  —  Phrynosoma,  the  horned  toad.     Photo,  by  E.  R.  D. 

cross  bands  above,  with  iridescent  colors  on  the  throat  of 
the  male,  and  with  large,  strongly  keeled  scales  and  a 
slender  tail.  The  largest  of  the  Iguanidae  is  the  "  leguaii " 
of  the  West  Indies  and  South  America,  which  gains  a 
length  of  1.75  metres,  or  over  five  feet. 

The  family  Varanidae,2  or  water-lizards,  contains  the 
largest  known  lizards.  The  Nile  varanus  attains  a  length 
of  nearly  two  metres.  It  lives  on  the  rivers  of  Africa, 
feeds  on  small  Crustacea,  birds,  birds'  eggs,  frogs,  fish,  and 
occasionally  also  on  young  crocodiles  and  crocodile  eggs. 

1  Fig.  251.  2  Latinized  from  the  Arabic  word  waran,  lizard. 


270 


ZOOLOGY 


The  ancient  Egyptians  regarded  these  crocodile-like  lizards 
as  the  greatest  enemies  of  the  crocodile. 

The  Lacertidae,1  which  are  common  in  middle  and  south- 
ern Europe,  are  agile,  harmless  creatures,  often  of  bright 
colors,  and  are  commonly  and  favorably  known.  The  more 


FIG.  252.  —  Lacerta  viridis,  the  green  lizard  of  Europe.    After  Brehm. 

abundant  are  the  "green  lizard"  (Fig.  252),  the  "sand- 
lizard,"  and  the  "  wall-lizard  "  of  the  Latin  countries. 

The  Helodermidae  include  the  largest  lizard  of  the 
United  States,  the  so-called  "  Gila  monster,"  which  in- 
habits New  Mexico,  Arizona,  and  the  country  southward. 
The  lizard  is  colored  brown,  with  reddish  spots  and  numer- 

1  From  lacerta,  lizard. 


THE  LIZARD  AND  ITS  ALLIES 


271 


ous  yellowish  punctations  (Fig.  253).  It  is  nocturnal  in 
its  habits  and  its  bite  is  very  poisonous,  although  not  often 
fatal  to  man. 

The  family  Anguidae,  or  slow-worms,  includes  the  famous 
glass-snake  or  joint-snake  of  the  South.  *  This  snake-like 
lizard  has  no  legs,  or  only  rudiments  of  the  hinder  pair. 
It  is  noted  for  the  ease  with  which 'it  breaks  in  two  when 


FIG.  253.  —  Heloderma,  the  Gila  monster.     About  two-fifths  nat.  size. 
From  Brehm. 


struck  or  lifted  by  the  tail.  This  result  is  due  to  the  fact 
that,  as  in  certain  other  lizards,  the  vertebriB  of  the  tail  are 
unossified  along  the  middle  plane,  so  that  they  separate 
at  this  point  upon  the  slightest  blow.  The  muscles  of  this 
species  seem  also  to  be  arranged  so  as  to  facilitate  sepa- 
ration. In  Europe  there  is  a  lizard  of  this  family,  the 
so-called  "  blind- worm  "  (having,  however,  well-developed 


272  ZOOLOGY 

eyes),  which  is  found  in  retired  localities,  from  which  it 
comes  out,  especially  in  the  evening,  to  capture  earth- 
worms and  slugs. 

.  The  Chameleon  famed  in  literature  comes  from  Africa. 
Its  change  of  color  depends  upon  the  possession  of  several 
layers  of  different  color  in  the  skin,  which  layers  can  be 
separately  expanded  or  contracted  as  required,  as  a  result 
of  which  some  one  color  comes  to  predominate.  It  cap- 
tures insects,  a  habit  which  is  facilitated  by  its  power  of 


FIG.  254.  —  Chameleo,  the  chameleon.     From  Leunis. 

protruding  the  tongue  to  over  half  the  length  of  its  body 
and  bringing  the  sticky  end  in  contact  with  its  prey.  The 
protrusions  and  retractions  of  the  tongue  are  effected  with 
marvellous  rapidity  (Fig.  254). 

While  in  point  of  size  the  lizards  of  geologically  recent 
times  are  inconsiderable,  those  of  former  epochs  were 
huge.  These  former  or  fossil  lizards  were  most  charac- 
teristic of  the  middle  life  era  or  the  Mesozoic  age.  They 
belong  to  three  main  groups;  namely,  swimming,  walking 
or  wading,1  and  flying  lizards.  The  swimming  lizards  were 

1  Fig.  254. 


THE  LIZARD  AND   ITS  ALLIES 


278 


sometimes  over  10  metres  long,  and  had  feet  modified 
as  paddles.  The  land  lizards  were  elongated,  three-toed, 
carnivorous  reptiles,  with  hollow  leg  bones  like  birds.  In 
the  flying  lizards,  a  strong  compact  body  was  provided 
with  hollow,  air-filled  bones,  and  locomotion  was  effected 
by  a  huge  membranous  expanse  stretched  between  the 


FIG.  255.  — Hadrosaurus.    From  reconstruction  model.     Osborn,  "  Kept. 
Amer.  Mus.  Nat.  Hist." 


elongated  posterior  finger,  the  trunk,  and  the  hind  legs. 
The  spread  of  the  wing  was  about  three  feet. 

The  Chelonia,1  or  turtles,  form  an  order  distinct  from 
the  lizards.  ,  They  are  characterized  by  a  depressed  form, 
a  bony  case,  and  toothless  jaws.  Like  other  reptiles,  they 
are  most  abundant  in  tropical  countries,  since  the  high 

i/r/,  turtle. 


274  ZOOLOGY 

external  temperature  compensates  in  a  way  for  the  insuf- 
ficiency of  the  mechanism  for  maintaining  from  the  inside 
a  high  blood  temperature.  Turtles  are  abundant  in 
Africa,  and  are  much  commoner  in  North  America  than 
in  Europe.  Three  families  of  Chelonia  may  be  distin- 
guished. A  short  account  of  each  follows. 

The  family  Chelonidae  includes  certain  marine  turtles. 
Turtles  live  in  all  oceans  and  may  acquire  a  weight  of  as 


FIG.  2f)t>. — Hawkbill-turtle.     Much  reduced.     From  Brehm. 

much  as  one  thousand  pounds.  The  green-turtle,  used  in 
making  soup,  occurs  on  the  Atlantic  coast  as  far  north  as 
Long  Island.  From  the  hawkbill-turtle  (Fig.  256)  comes 
the  tortoise  shell  used  in  certain  ornaments.  In  the 
leather-back  the  shields  are  incompletely  ossified. 

The  family  Trionychidae 1  includes  our  soft-shelled  tur- 
tles, which  live  in  rivers  or  ponds  of  the  Mississippi  valley 
and  the  Gulf  drainage  basin  (Fig.  257). 

1  T/O/J,  thrice  ;  8vv%,  claw. 


THE  LIZARD  AND  ITS  ALLIES 


275 


The  family  Testudinidae :  includes  the  hard-shelled, 
fresh-water  and  land  tortoises.  Our  snapping-turtle  is 
distributed  from  Canada  to  equa- 
torial South  America.  It  feeds 
on  fish  and  lays  from  forty  to  fifty 
eggs,  which  it  buries  at  a  depth  of 
about  a  metre.  The  alligator 
snapper  of  the  Gulf  States  attains 
the  length  of  a  metre,  and  is  re- 
garded as  the  "  most  ferocious  and, 
for  its  size,  the  strongest  of  all 
reptiles."  The  box-tortoises  oc- 
cupy the  northeastern  and  central 
parts  of  North  America.  They 
are  well  known  by  the  fact  that 
the  body  is  short  and  high,  the 
plastron  is  provided  with  a  mov- 
able hinge,  and  the  carapace  is 
colored  black  and  yellow.2  Other 


FIG.  257.  —  Trionyx,  three- 
clawed  turtle  of  the  Mis- 
sissippi valley.  Keduced. 
From  Leunis. 


FIG.  258. —  Terrapene  Carolina,  the  box-tortoise.     Photo,  of  living  animal 
by  W.  H.  C.  P. 


1  From  testa,  a  shell. 


2  Fig.  258. 


276 


ZOOLOGY 


common  tortoises  of  the  eastern  United  States  are  the  musk- 
turtle,  told  by  a  strong  odor  of  musk  ;  the  painted  turtle, 
of  greenish  black  color  and  with  marginal  plates  marked 
with  bright  red  ;  the  speckled  tortoise,  black  Avith  round 
orange  spots  ;  and  the  wood  tortoise,  with  keeled  shell, 
and  plates  marked  with  concentric  striae. 

The  order  Ophidia l  comprises  the  snakes,  characterized 
bjr  the  elongated  body  without  appendages,  and  by  the 


FIG.  259.  —  Eutamia,  garter-snake,  dorsal  view.    Photo,  by  E.  R.  D. 

absence  of  eyelids.  Like  other  reptiles,  the  snakes  are 
chiefly  tropical,  but  inhabit  also  the  temperate  zones.  They 
feed  on  living  animals. 

The  family  Colubridae 2  includes  the  great  majority  of 
our  common  non-venomous  snakes,  such  as  the  garter- 
snake,3  water-snake,  black-snake,  milk-snake,  and  spread- 
ing adder.  Allied  are  the  boas  of  South  America  and  the 
pythons  of  India,  which  attain  the  length  of  six  metres  or 

1  60is,  serpent.  2  coluhra,  serpent.  8  Fig.  259. 


THE  LIZARD  AND  ITS  ALLIES 


277 


more.  Xot  being  poisonous  their  bite  is  not  dangerous, 
but  they  attack  large  birds  and  even  medium-sized  mam- 
mals arid  crush  them  to  death  in  the  folds  of  their  body. 

The  family  Elapidae l  includes  the  large  venomous  ser- 
pents of  the  East,  the  cobra  of  the  East  Indies,  and  the  asp 
of  the  Egyptians.  The  bite  of  these  serpents  is  quickly 


FIG.  2HO.  —  Elapx  corallina,  a  harlequin  snake  of  South  America  allied  to  the 
bead-snake  of  the  South.    From  "  Standard  Natural  History,"  after  Brehm. 

fatal  to  man.  To  this  family  belongs  also  the  bead-snake 
of  our  Southern  States,  which  is  however  harmless  (Fig. 
260). 

The  Crotalidae  2  include  the  rattlesnakes,  characteristic  of 
America.3     Of  this  family  the  most  dangerous  is  the  water- 

1  €\a\f/.  an  unknown  snake  of  the  ancients. 

2  ,  clapper.  3  Figs.  261,  262. 


278 


ZOOLOGY 


FIG.  2(51.  —  Crotalus,  the  rattlesnake.    Photographed  as  the  snake  was  about 
to  strike.    Taken  in  Arizona  and  kindly  lent  by  H.  W.  Menke,  Chicago,  111 


FIG.   262.  —  The   rattlesnake.     The   recoil  after   striking.      Photographed 
Arizona  and  kindly  lent  by  H.  W.  Menke. 

Note  in  both  figures  the  elevated  rattle,  toward  the  right. 


THE  LIZARD  AND   ITS  ALLIES  279 

moccasin  or  black  moccasin,  which  inhabits  the  Southern 
States,  and  gives  no  warning  noise  as  does  the  rattlesnake. 
The  copperhead  of  the  eastern  half  of  the  United  States  is 
also  dangerous,  bnt  is  mostly  confined  to  wooded,  moun- 
tainous regions.  The  rattlesnake  was  once  common  over 
the  whole  of  the  Northern  States  as  far  west  as  the  Rocky 
Mountains,  but  it  is  now  nearly  exterminated  in  well- 
settled  districts.  Related  to  these  are  the  venomous 
vipers  of  Europe. 

The  order  Crocodilina  contains  only  some  twenty  species, 
distributed  in  three  genera.     The  gavial  is  the  crocodile 


FIG.  263. —  Head  of  Alliyaior  mississippiensis,  the  Mississippi  alligator. 
From  Leunis. 


of  the  Ganges  River.  It  captures  even  large  mammals 
and  man.  The  crocodile  in  the  strict  sense  is  found  in  the 
Nile  and  other  African  rivers,  in  certain  countries  on  the 
western  border  of  the  Pacific,  and  in  northern  South 
America,  Central  America,  and  the  Antilles.  The  American 
alligator,  which  has  a  different  arrangement  of  the  denti- 
tion from  the  crocodiles,  occurs  in  seven  slightly  differing 
species,  all  of' which  are  South  American  excepting  the  alli- 
gator of  our  Southern  States.  It  feeds  on  fish,  and  attacks 
horses  and  even  man  (Fig.  263). 


280 


ZOOLOGY 


APPENDIX   TO   CHAPTER   XVIII 

KEY    TO    THE    FOUR    OKDEKS    OF    REPTILES 

Trunk  enclosed  in  a  case  composed  of  a  dorsal  and 
a  ventral  shield  (carapace  and  plastron)  ;  jaws 

without  teeth ."'-..          Chelonia 

Without  encasing  shields  ;  teeth  on  jaws. 
?>i.   Teeth   in  special   cups  or   alveoli ;     4    legs ; 

cloacal  opening  a  longitudinal  slit       ..  '     .        Crocodilina 
&:>.    Teeth  not  in  special  alveoli ;  cloacal  opening  a 

transverse  slit. 
Ci.    Shoulder  girdle   and   sternum    present ; 

eyelids  usually  present         .        .        .  Sauna, 

c-j.    Shoulder  girdle  and  sternum  absent ;  eye- 
lids absent ;  no  feet      .       _.        .        .  Ophidia 


CHAPTER   XIX 
THE  ENGLISH  SPARROW  AND  ITS  ALLIES 

THE  term  "  English "  sparrow  is  somewhat  of  a  mis- 
nomer, for  at  the  time  it  was  introduced  into  our  country 
this  bird  ranged  over  all  Europe,  where  it  is  known  as  the 
house  sparrow.  The  history  of  the  spread  of  this  bird 
shows  us  in  a  vivid  way  what  are  the  successful  qualities 
among  birds.  Originally  this  sparrow  was  conhned  to 
middle  Europe,  and  probably  made  its  way  into  Germany 
at  the  time  of  the  Romans.  It  has  since  swept  all  over 
Europe,  including  the  British  Isles,  and  has  penetrated 
even  into  Siberia.  It  has  crossed  the  Mediterranean  and 
is  found  along  the  Senegal  River,  and,  probably  through 
human  agency,  has  penetrated  to  the  Cape.  It  has  been 
transplanted  voluntarily  by  man  to  North  America, 
Australia,  and  Java.  It  seems  to  occupy  among  birds  the 
place  taken  among  mammals  by  the  rats.  Crafty,  pugna- 
cious, obtrusive,  thieving,  dirty,  it  has  become  a  nuisance 
wherever  it  has  penetrated.  But  just  these  pushing  quali- 
ties, combined  with  small  size,  great  hardiness,  a  universal 
diet,  and  immense  fecundity,  have  enabled  it  to  make  its 
way  against^  all  competitors.  Its  introduction  into  America 
can  only  be  regarded  as  a  deplorable  blunder. 

Spread  of  English  Sparrow  in  America. — The  first  im- 
portations of  the  house-sparrow  (Passer  domesticus)  to 
North  America  were  made  at  Brooklyn,  New  York,  in  1850 

281 


282  ZOOLOGY 

and  1852.  The  second  importation  survived  and  multiplied. 
Subsequent  importations  were  made  to  Maine,  Rhode 
Island,  and  Pennsylvania,  so  that  by  1870  the  sparrow 
was  firmly  established  in  the  eastern  United  States.  From 
this  time  on  the  sparrow  spread  at  a  rate  unparalleled  by 
any  native  bird.  By  1886  it  had  spread  as  far  west  as 
Kansas,  and  had  established  colonies  at  Salt  Lake  City, 
San  Francisco,  and  other  outlying  regions  ;  and  through- 
out this  territory  it  occurred  in  great  abundance.  Since 
then  it  has  penetrated  west  to  the  Rocky  Mountains,  and 
south  to  Texas.  This  extraordinary  spread  has  been  due 
to  several  causes.  As  already  suggested,  the  bird  can 
adapt  itself  to  various  climatic  conditions,  and  its  fecundity 
is  very  great.  Thus  in  our  Southern  cities  there  are  from 
five  to  six  broods  a  year,  and  from  four  to  six  young  in 
each  brood.  Assuming  that  twenty-four  young,  half  of 
them  females,  are  produced  by  a  pair  each  year,  and  that 
all  the  females  breed  when  one  year  old,  and  successively 
for  ten  years,  and  that  there  are  no  deaths,  then  in  the 
tenth  year  138,000,000,000  individuals  will  have  been  pro- 
duced from  the  original  pair.  To  the  realization  of  the 
possible  maximum  of  reproduction  there  are,  however, 
many  checks,  especially  the  destruction  of  birds  by  ac- 
cidents, disease,  and  beasts  arid  birds  of  prey. 

Food  of  English  Sparrow.  —  The  house-sparrow  was  in- 
troduced for  the  purpose  of  destroying  or  holding  in  check 
the  "canker-worm"  and  the  various  other  caterpillars  which 
destroy  our  fruit,  forest,  and  shade  trees.  There  is  much 
doubt,  however,  whether  the  house-sparrow  is  at  all  effi- 
cient in  the  way  of  destroying  insect  pests,  while  it  is 
quite  certain  that  it  fights  with  and  drives  away  our 
native  insect-eating  birds.  More  important  still,  it  de- 


THE  ENGLISH   SPARROW  AND  ITS  ALLIES        283 

stroys  large  quantities  of  grain  in  the  field,  as  well  as 
many  kinds  of  garden  produce,  so  that,  on  the  whole,  the 
English  sparrow  must  be  reckoned  destructive  to  agri- 
culture. Of  late  years  it  has  come  into  our  Southern 
markets  as  a  substitute  for  the  rice-bird. 

Increase  of  Exotic  Species.  —  The  extraordinary  spread 
of  the  English  sparrow  after  importation  to  this  country 
is  not  wholly  explained  by  its  large  fecundit}^;  for  although 
equally  reproductive  in  Europe,  it  increases  less  rapidly 
there  than  here.  Also  it  is  not  due  to  any  peculiarity  of 
our  country,  for  the  bird  is  a  similar  pest  in  Australia. 
Similar  facts  concerning  the  spread  of  other  animals  lead 
us  to  conclude  that  it  is  the  new  country  which  permits 
the  rapid  spread  and  consequent  destructiveness.  Thus 
when  the  cabbage-butterfly  (^Pieris  rapce)  was  brought  to 
this  country  it  spread  with  such  rapidity  that,  starting  in 
1860  at  Quebec,  it  has  now  spread  all  over  the  United 
States  as  far  as  the  Rocky  Mountains.  Again,  the  grape- 
vine insect  pest,  Phylloxera,  a  native  of  this  country,  but 
not  particularly  destructive  here,  has  been  accidentally 
transported  to  France,  and  there  it  has  wrought  great 
havoc  in  the  vineyards.  Another  instance,  this  time  of 
an  aquatic  animal,  shows  the  same  result :  the  periwinkle, 
Littorina  littoria,  now  the  commonest  snail  on  the  seashore 
north  of  New  York,  has  migrated  down  the  shore  from 
Halifax  since  1868.  This  old  species  in  the  new  country 
has  almost  driven  out  the  other  shore  mollusks,  to  such  an 
extraordinary  degree  has  it  multiplied.  Now  why  should 
animals  in  a' new  country  develop  with  such  unusual  rapid- 
ity ?  It  is  because  coming  into  a  new  country  they  have 
left  behind  them  their  natural  enemies,  and  there  has  not 
yet  been  time  for  them  to  acquire  new  ones.  Eventually 


284 


ZOOLOGY 


the  new  enemies  are  gained  or  their  bid  ones  overtake 
them,  and  then  the  numbers  of  the  exotic  form  become 
reduced  ;  a  new  equilibrium  becomes  established. 

The  English  sparrow  belongs  to  the  family  Fringillidae, 
which  includes   sparrows   and   finches.      This  is   a  large 


FIG.  1?(J4.  —  The  American  crossbill  (Loxia  curvirostra) . 

family,  comprising  over  live  hundred  species,  found  in  all 
parts  of  the  world,  excepting,  originally,  Australia.  In 
the  United  States  this  is  the  largest  family  of  birds,  com- 
prising in  most  places  about  one-seventh  of  the  species. 
Among  common  or  striking  native  Fringillidse  may  be 


THE  ENGLISH  SPAKTIOW  AND   TTS  ALLIES        285 

mentioned  the  crossbills,1  yellow-bird,  vesper-sparrow, 
white-throated  sparrow,  tree -sparrow,  dripping-sparrow,2 
snow-bird,  song-sparrow,  fox-sparrow,  chewink,  cardinal 
grosbeak,  rose-breasted  grosbeak,  and  indigo-bird.  Most 
of  these  birds  are  known  to  every  country  boy. 

The  family  of  Turdidae,   or  thrushes,   includes  several 
common    American    birds,  —  the    robin,    abundant    about 


FIG.  2fi5.  — Chipping-sparrow  (Sp/.zella  socialis). 

houses  during  the  summer  but  for  the  most  part  migrat- 
ing south  from  New  England  during  the  winter ;  the  wood 
or  song  thrush,3  one  of  our  finest  songsters ;  the  bluebird, 
one  of  the  earliest  of  our  migrants,  with  "  the  sky  on  its 
back  and  the  earth  on  its  breast." 

The  family  of  Sylviidae  comprises  the  "  warblers  "  of  the 
Old  World'.  Here  belongs  the  European  nightingale.  Its 
common  representative  in  this  country  is  the  ruby-crowned 
kinglet  (Fig.  267). 

1  Fig.  264.  2  pig<  265.  3  Fig.  266. 


286 


ZOOLOGY 


The  family  of  Paridae  includes  the  titmice,  or  tits  and 
nuthatches.  The  tits  are  chiefly  Old  World  birds,  but  we 
have  a  common  representative  in  the  black-capped  chicka- 
dee, well  known  from  its  cheerful  whistle.  In  this  family 


FIG.  26(5. —Wood-thrash  (Turdus  mustelinus). 


belong  the  nuthatches  which  run  over  tree-trunks,  head 
up  or  down,  indiscriminately  (Fig.  268). 

The  family  of  Certhiidae  includes  the  little  brown  creeper 
which  runs  over  tree-trunks  much  as  the  nuthatches  do 
and  uses  its  tail-feathers  as  props  against  the  tree-trunk 
(Fig.  269). 


THE  ENGLISH  SPARROW  AND  ITS  ALLIES        287 


The  Troglodytidae,  or  wrens, 
are  characteristic  of  South 
America,  but  some  have  spread 
into  North  America  and  north- 
ern Europe.  Our  house-wren, 
which  is  a  near  relative  of  the 
European  house-wren,  is  an  ac- 
tive little  brown  bird,  with  a 
sharply  bent-up  tail.1  In  this 
same  family  belong  the  mock- 
ing-birds, the  centre  of  whose 
distribution  is  Central  America, 
the  West  Indies,  and  the  south- 


FIG.  268.  —  White-breasted  nuthatch  (Slthi 

carolinensis) . 


FIG.  42(>7.  —  Golden-crowned  king- 
let (Reyulus  satrapa). 

ern  United  States.  The 
large  brown  thrasher  and 
the  cat-bird  are  familiar 
over  the  country.  The 
mocking-bird  does  not 
get  far  north  into  New- 
England.  It  is  regarded 
by  many  as  superior  to 
the  nightingale  as  a 
singer. 

The  family  of  Mnioti- 
lidae,  or  "  wood  -  war- 
blers," is  the  peculiar 
glory  of  America.  It 

i  Fte.  270. 


288 


ZOOLOGY 


contains  numerous  small,  mostly  brilliantly  colored  birds, 
which  migrate.  Although  a  few  of  them — like  the  red- 
start, the  Maryland  yellow-throat  (Fig.  271),  the  redpoll 
warbler,  the  chestnut-sided  warbler,  and  the  yellow  war- 
bler—  are  abundant,  few  of  the  thirty -five  or  forty  Eastern 


FIG.    2(59.  —  Brown     creeper 
( Cerithia  familiari*) . 


FIG.  270.  — House-wren  (Troglodytes  ai'don). 


species  can  be  said  to  be  commonly  known  except  to 
careful  observers  of  birds  ;  for  during  the  migrations 
they  hide  in  thickets,  and  are  extremely  shy. 

The  Vireonidae  include  the  vireos,  or  greenlets,  bright, 
handsome,   and  exclusively  American  birds.     The  com- 


THE  ENGLISH  SPARROW  AND  ITS  ALLIES        289 

monest  species  are  the  red-eyed  vireo  (Fig.  272)  and  the 
yellow-throated  vireo. 

The  Laniidae,  or  shrikes,  are  of  world- wide  distribution. 
They  are  vigorous,  pugnacious  birds,  which  have  the  habit 


FIG.  271. —  Maryland  yellow-throat  (Geothlypis  trichas). 

of  impaling  grasshoppers  and  other  small  animals  upon 
thorns,  and  leaving  them  there.  In  Germany  there  is  a 
tradition  that  the  shrike  daily  impales  nine  victims,  and  it 
is  hence  commonly  called  Neuntodter,  or  "  ninekiller."  The 


290 


ZOOLOGY 


FIG.  272.  — Red-eyed  vireo  (Vireo  olivaceus). 


FIG.  273.  —  Great  northern  shrike  (Lanius  boreal  i 


THE  ENGLISH  SPARROW  AND  ITS  ALLIES 


291 


impaling  seems  to  be  done  chiefly  in  the  winter  time,  and 
apparently  has  for  its  purpose  the  storing  of  food  against 
possible  famine.  Among  birds  frequently  destroyed  by 
them  is  the  English  sparrow,  and  it  has  been  suggested  that 
the  shrikes  should  be  encouraged  to  live  in  parks  of  cities 


FIG.  274. —  Cedar  waxwing  (Ampelis  cedrontm). 

infested  by  sparrow  pests ;  but  unfortunately  the  shrikes 
do  not  confine  themselves  to  this  intruder.  We  have  two 
species  of  shrikes,  a  northern  (Fig.  273)  and  a  southern. 
The  Ampelidae,  or  waxwings,  are  found  over  the  Northern 
Hemisphere.  They  are  migratory,  go  in  flocks,  feed  on 


292 


ZOOLOGY 


insects   and   fruits,   and    chatter  rather   than  sing.      Our 
commonest  species  is  called  " cedar-bird"  (Fig.  274). 


FIG.  275.  —  Barn-swallow  (Chplidon  ery  thro  ff after) . 

The  Hirudinidae,  or  swallows,  are  found  over  the  world. 
They  are  powerful  fliers,  and  are  insectivorous.  Formerly 
all  of  them  bred  in  boughs,  cliffs,  and  hollow  trees,  and 

some  species  still  retain  these 
habits.  The  best-known  species 
are  the  bank-swallows,  which, 
living  in  colonies,  form  numer- 
ous holes  in  railroad  cuts  and 
sandbanks  in  general  ;  the 
white-bellied  swallow,  abundant 
about  water  ;  and  the  barn-swal- 
low (Fig.  275),  with  a  chestnut 
belly,  which  builds  its  nest  in  the 
rafters  of  our  barns  (Fig.  276). 

The  Tanagridae,  or  tanagers,  are  exclusively  American, 
and  belong  especially  to  the  tropics.  They  live  in  the 


FIG.   276.  —  Nests  of  barn-swal- 
low.   Photo,  by  D.  and  S. 


THE  ENGLISH  SPARROW  AND  ITS  ALLIES        293 

woods,  and  feed  on  berries  and  fruits.  The  northernmost 
member  of  the  family  is  the  scarlet  tanager  of  the  eastern 
United  States  (Fig.  277). 

The  Icteridae  include  numerous  species  with  different 
habits.  These  are  also  confined  to  America,  and  are 
especially  abundant  in  the  tropics.  They  feed,  for  the 


FIG.  277.  —  Scarlet  tanager  (Pimnya  erythomelas}. 

most  part,  on  seeds.  The  commonest  representatives  are 
the  crow  blackbird,1  of  large  size  and  iridescent  plumage  ; 
the  Baltimore  oriole,  which  weaves  a  hanging  nest ;  the 
orchard  oriole,  with  less  orange  than  the  preceding ;  the 
large  meadow-lark,  brownish  above  and  yellow  below ; 
the  red- winged  blackbird  ;  the  cow-bird,  which  builds  no 
nest  but  lays  its  eggs  in  the  nests  of  various  small  birds  ; 


294  ZOOLOGY 

and  the  "bobolink,"  as  it  is  called  in  the  North,  whose  song 
is  the  merriest  of  all  birds.  In  the  South,  whither  the 
bobolink  migrates  in  the  winter,  it  is  a  great  pest  in 


FIG.  278.  —Purple  grackle  (Quiscalus  quiscula). 

the  rice-fields,  and  is   known  as  the  "rice-bird."     It  is 
slaughtered  there  as  a  game-bird. 

The  Corvidae  include  the  crows  and  their  allies,  all  of 
them  birds  of  large  size.  The  crow,  the  raven  of  the  West 
and  of  Europe,  and  the  blue  jay  (Fig.  279)  are  the  com- 
monest North  American  species  of  this  family. 


THE  ENGLISH   SPAEEOW  AND  ITS  ALLIES 


295 


The  Alaudidae,  or  larks,  are  a  family  chiefly  of  Old  World 
birds  of  dull  color,  building  a  rough  nest  on  the  ground, 
and  feeding  on  seeds  and  insects.  The  skylark  of  Europe 
is  renowned  as  a  songster.  In  this  country  we  have  one 


.  FIG.  279.  —  Blue  jay  (Cyanocitta  cristata). 

representative  of  the  family,  the  horned  lark,  found  also 
in  Europe. 

The  Tyrannidae,  or  flycatchers,  are  an  exclusively  Ameri- 
can family,  feeding  on  insects.     The  best-known  represen- 


296 


ZOOLOGY 


tatives  are  the  courageous  king-bird  (Fig.  280),  the  wood 
pewee  (Fig.  281),  and  the  water-loving  phoebe. 


FKJ.  280. — Kingbird  (Tyranmis  tyrannus). 


FIG.  281.  —  Nest  of  pewee.     Photo,  by  D.  and  S. 


THE  ENGLISH  SP  Alt  ROW  AND  ITS  ALLIES        297 

We  will  now  pass  in  brief  review  the  principal  Orders  of 
Birds  other  than  Passeres.  The  Psittaci  include  the 
parrots  and  cockatoos.  In  the  cockatoos  the  feathers  of 
the  head  are  elevated  to  form  a  crest.  In  the  parrots 
there  is  no  such  crest ;  in  one  subdivision  the  tail  is  long ; 
in  a  second,  very  short.  The  representatives  of  this 


FIG.  282. —  Conunts  carolinensis,  the 
Carolina  paroquet.  One-fifth  nat.  size. 
After  Wilson. 


family  are  found  almost  exclusively  in  the  tropics,  in 
Brazil,  the  Moluccas,  and  in  Australia.  In  general,  these" 
birds  have  a  loud  voice,  and  certain  species  may  be  trained 
to  articulate  words  and  combine  them  into  sentences. 
There  is  only  one  parrot  native  to  the  United  States  — 
the  Carolina  paroquet  (Fig.  282).  This  formerly  occurred 


298 


ZOOLOGY 


north  to  the  Ohio  River,  but  it  has  been  within  recent 
years  practically  exterminated  by  plumage  hunters. 

The  Raptores  include  eagles,  hawks,  and  falcons ;   the 
vultures;  condors;  and  owls.     These  birds  feed  chiefly  on 


FIG.  283. — Sharp-shinned  hawk   (Ac-       FIG.  281. — Screech  owl  (Meyascops 
cipiter  velox) .  asio) . 


birds  and  mammals,  which  they  capture  alive  in  their 
claws  or  beaks ;  a  few  live  on  carrion.  They  occur  in  all 
parts  of  the  globe.  The  bald  eagle,  used  as  a  symbol  of 
the  Republic,  is  the  commonest  of  our  eagles.  Among 


THE  ENGLISH  SPARROW  AND  ITS  ALLIES        299 

our  hawks,  the  sparrow-hawk,  which  is  only  about  the 
size  of  the  robin,  is  one  of  our  commonest ;  others  are 
the  sharp-shinned  hawk,  which  kills  birds  almost  ex- 
clusively, and  is  especially  destructive  to  poultry,1  and 
Cooper's  hawk,  which  is  also  destructive  to  birds.  These 
two  hawks  have  practically  no  redeeming  qualities,  ex- 
cept the  fact  that  they  prey  upon  the  English  sparrow. 
The  vultures  are  represented  in  our  fauna  by  the 
turkey-buzzard,  Avhicli,  like  other  members  of  the  family, 
feeds  on  carrion.  The  European  and  African  vultures 
even  exceed  the  turkey-buzzard  in  size.  The  condor 
is  the  largest  of  the  American  Raptor es.  It  preys  even 
upon  live  sheep  and  calves.  The  owls,  which  live  in  dark 
holes  and  feed  upon  small  mammals  at  night,  are  found 
over  the  globe.  Our  commonest  species  is  the  reddish 
gray  screech-owl.2  The  great  horned  owl  is  an  inhabitant 
of  wooded  tracts,  and  is  destructive  to  poultry  and  small 
mammals.  The  snowy  owl  is  one  of  the  handsomest  of  all 
owls,  and  is  frequently  seen  stuffed  in  houses  in  Europe 
as  well  as  in  North  America. 

The  Scansores  include  the  toucans  and  cuckoos  on  the 
one  hand  and  the  woodpeckers  on  the  other.  The  toucans 
are  characterize^!  by  an  enormous  bill,  which  in  extreme 
cases  is  as  long  as  the  rest  of  the  bird.  It  would  be  ex- 
tremely heavy  were  it  not  filled  with  air  spaces  of  great 
extent.  These  birds  inhabit  Brazil.  The  great  bills  are 
of  use  in  feeding  on  fruits.  Filling  the  place  in  the  Old 
World  of  the  toucans  of  the  New  are  the  hornbills  of 
Africa  and  Asia,  which  are  likewise  frugivorous.  The 
cuckoos  are  typically  represented  by  the  Old  World 
cuckoos.  Like  our  own  cow-bird,  they  have  the  peculiar 
ig.  283,  2  j^.  284. 


300 


ZOOLOGY 


habit  of  laying  their  eggs  in  the  nests  of  other  birds,  espe- 
cially insectivorous  birds,  where  they  are  brooded  and  the 
young  are  fed  by  the  foster-mother.  Our  native  cuckoo, 
however,  broods  its  own  eggs,  and  is  a  useful  insectivo- 
rous bird.  The  kingfishers  are  also  placed  in  this  group. 


•.  ••  ' ''  '"-'•C:;/3^'-- 
Fio.  285.  —  Belted  kingfisher  ((Jenjle  alcyon}. 

They  are  especially  an  Old  World  family,  but  one  genus, 
Ceryle,  has  found  its  way  into  North  America  and  even 
into  South  America.  These  birds  feed  chiefly  on  fish,  and 
they  have  gained  a  compact  oily  plumage  to  prevent  them 
from  getting  wet  when  they  plunge  for  their  prey.  Our 
species  is  known  as  the  belted  kingfisher  (Fig.  285^). 


THE  ENGLISH  SPAEEOW  AND  ITS  ALLIES       301 


The  woodpeckers  include  for  the  most  part  arboreal 
birds  which  feed  chiefly  on  insects  and  have  loud,  harsh 
cries.  The  common  idea  that  they  are  sap-suckers  and 
destructive  to  trees  seems  to  be  true  only  of  one  of  our 
species  —  the  yellow- 
bellied  woodpecker. 
The  heavy,  long  bill 
enables  woodpeckers 
to  peck  holes  in  trees 
for  wood-eating  in- 
sects, and  the  long, 
barbed,  protrusible 
tongue  aids  in  remov- 
ing the  prey.  Our 
commonest  woodpeck- 
ers are  the  golden- 
winged  woodpecker,  or 
flicker,1  the  red-headed 
woodpecker,  the  hairy 
woodpecker,  and  the 
d  o  w  11  y  woodpecker. 
An  interesting  ques- 
tion concerning  the 
golden -winged  wood- 
peckers of  the  East  and 
Southwest  is  whether 

. ,  i     -I     •  T  i  FIG.  28(5. — Flicker  (Cotaptes  auratus) . 

they   hybridize  where 

their  areas  of  distribution  overlap. 

The  Cypselomorphae  include  fhe  humming-birds,  swifts, 
and  goat-suckers.  The  humming-birds  are  mostly  small 
species,  limited  to  our  hemisphere,  and  characteristic  of 

i  Fig.  286. 


302 


ZOOLOGY 


the  tropics.      One  species,   the   ruby-throated   humming- 
bird, reaches  New  England  and  Canada.     These  usually 

brilliantly  colored 
birds  feed  on  insects 
and  nectar,  which  they 
gather  from  floAvers. 
They  fly  with  great 
swiftness,  nest  in  trees, 
and  lay  only  two  white 
eggs  (Fig.  287). 

The  Swifts  have  a 
broad  gape,  and  no 
bristles  at  the  base  of 
the  bill.  They  have 
habits  much  like  swal- 
lows, and  are  found 
especially  in  the  warm 
parts  of  the  world. 

FIG-  287.  —  Ruby-throated  humming-bird        \  . 

(Trochilux  colubns).  Most    Species     OI     this 

family    have    salivary 


FIG.  288.  —  Nest  of  chimney-swift.    Photo,  looking  down  chimney,  hy  D.  and  S. 


THE  ENGLISH  SPAEROW  AND   ITS  ALLIES       303 


glands,  whose  secretions  aid  in  cementing  the  nest.  Our 
common  representative  of  this  group  is  the  chimney-swift, 
or  chimney-swallow.1  Certain  Chinese  species  make  nests 
entirely  of  the  mucilaginous  secretion  of  the  salivary 
glands  ;  these  constitute 
the  edible  birds'-nests 
of  the  Chinese.  The 
goat  -  suckers  include 
night-flying  birds,  with 
exceedingly  broad  gape 
and  insectivorous  habits. 
The  night  -  ha\vk  of 
North  America,  and  the 
whippoorwill,  noted  for 
its  characteristic  night 
cry,  are  familiar  ex- 
amples. 

The  order  Columbinse 
includes  the  pigeons  and 
allies,  characteristic  of 
the  Eastern  Hemisphere. 
The  most  interesting 
species  of  the  group  — 
the  dodo  and  the  soli- 
taire, formerly  inhabit- 
ants of  the  islands  of 
Mauritius  and  Rodri- 
guez, respectively  — 
have  become  extinct  within  historic  times  through  the 
settlement  of  these  islands  by  white  men.  These  birds 
had  rudimentary  wings  and  tail.  Their  nearest  living 

i  Fig.  288. 


FIG.  289.  —  Passenger  pigeon  (Ectoplstes 
miyratorlus) . 


304 


ZOOLOGY 


ally  seems  to  be  the  "manu-mea1 "  of 'the  Samoan  Islands. 
The  pigeons  proper  are  represented  in  North  America  by 
three  wild  species  (Fig.  289).  The  domesticated  pigeon, 
Ootumba  livid,  is  a  native  of  southern  Europe  or  western 
Asia. 

The  order  Gallinacei  includes  a  number  of  terrestrial 
birds  of  large  size,  especially  the  grouse  or  partridges,  the 
pheasants  and  common  fowl,  the  guinea  fowl,  and  the  tur- 


FIG.  290.  —  Ruffed  grouse  (Bonasa  umbellus). 

keys.  On  account  of  their  large  size  and  well-flavored 
flesh,  they  are  much  used  as  human  food.  The  grouse 
of  America  include  the  familiar  "  bob-white  "  or  quail, 
which  is  undergoing  a  rapid  extermination  in  populous 
regions  ;  the  Canada  grouse,  which  does  not  occur  south 
of  New  York;  the  ruffed  grouse  of  the  Eastern  States;2 
and  the  prairie  chicken  of  the  Great  Plains,  which  has 
also  become  almost  exterminated.  In  Europe  the  large 

1  Red-bird.  2  Fig.  290. 


TIIK   ENdLfSII    SPARROW  AND  ITS  ALLIES       305 

"  capercallie  "  and  the  blackcock  are  favorite  game-birds. 
The  pheasants  are  characteristic  of  southern  Asia  and 
China;  they  comprise  some  of  the  most  brilliantly  colored 
and  greatly  ornamented  of  birds,  such  as  the  peacock  and 
the  golden  pheasant.  Here  also  belong  our  barnyard 
fowl,  derived  from  a  wild  species,  Grallus  bankiva,  inhabit- 
ing northern  India,  the  Kast  Indies,  and  the  Philippines. 
The  guinea-fowl  is  a  native  of  Africa,  where  it  goes  in 
large  flocks  and  is  difficult  of  approach.  The  turkeys 
are  North  American  birds.  The  wild  turkey  formerly 
occurred  over  all  the  United  States  and  Mexico.  It  was 
first  taken  to  Europe  in  1524,  was  domesticated  there,  and 
now  occupies  much  of  its  former  habitat  as  a  domesticated 
fowl.  From  this  brief  view  we  see  that  the  family  of  (lal- 
linacei  is,  for  man  at  least,  one  of  the  most  important 
families  of  birds. 

The  Grallatores,  or  waders,  include  a  great  number  of 
shore  birds  known  as  plovers,  sandpipers,  snipes,  rails, 
cranes,  herons,  and  storks.  The  plovers  walk  and  fly 
along  shore,  picking  up  worms,  mollusks,  and  amphibians; 
the  golden  plover  and  the  killdeer  are  well-known  game- 
birds.  The  snipes  are  found  in  meadows  or,  less  com- 
monly, in  woods.  One  of  the  most  common  is  the  spotted 
sandpiper,  also  called  u  tip-up  "  from  its  rocking  move- 
ments (Fig.  291).  It  is  seen  walking  around  small  pools 
of  water  by  the  roadside  or  in  fields.  Along  the  coast 
are  found  woodcock  and  large  snipes.  Among  the  herons, 
our  great  blue  heron  attains  a  length  of  four  feet  and  is 
a  notable  resident  of  swampy  regions;  the  egrets  have 
been  practically  exterminated  to  meet  the  demands  of 
milliners  ;  the  bittern  is  still  common  on  tide-flats. 

The    Natatores,  or  swimmers,  comprise  the  ducks  and 


306 


ZOOLOd Y 


geese,  the  pelicans,  the  petrels,  the  gulls  and  terns,  and 
the  divers.  Of  the  geese,  the  wild  goose,  or  Canada  goose, 
is  most  commonly  seen  in.  its  migrations.  Of  the  native 
ducks  we  have  many  kinds,  almost  all  rapidly  disappear- 
ing before  the  u  sportsman."  The  pelicans  are  large  fisli- 
eating  birds,  with  a  huge  bag-like  lower  bill.  In  this 
country  the  white  pelican  is  not  uncommon.  The  large- 


FIG.  291.  —  Spotted  sandpiper  (Actitis  macularia). 

winged  petrels  follow  in  the  wake  of  coastal  vessels.  The 
terns,  which  are  slender  birds  with  a  straight  bill,1  Avere 
once  abundant  along  our  coast,  but  have  been  decimated  to 
"  ornament "  bonnets.  The  gulls,  which  are  heavier  than 
the  terns  and  have  hooked  bills,  are  still  abundant  over 
all  bodies  of  water.  Finally,  the  loons  are  large  birds, 

i  Fig.  292. 


THE  ENGLISH  SPARROW  AND  ITS  ALLIES       807 

powerful  fliers  and  swimmers,  which  are  found  in  the 
lakes  of  the  Northern  Hemisphere.  They  are  quick 
divers,  and  can  swim  under  water  for  a  considerable 
distance. 

The  order  of  Cursores  includes  the  African  ostrich,  the 
American  ostriches  or  rheas,  the  cassowaries  of  the  East 
Indies,  and  certain  wingless  birds  of  New  Zealand  (Ap- 


FKJ.  292.  —  Common  tern  (Sterna  hirundo}. 

teryx  *) .  These  are  regarded  as  the  most  lowly  developed 
of  the  birds  ;  the  vanes  of  their  feathers  are  not  united, 
but  separate  to  form  a  sort  of  hair-like  covering  to  the 
body.  The  African  ostrich  is  the  largest  living  bird.  It 
wanders  in  families  or  flocks  in  the  deserts  of  Africa,  and 
feeds  on  grass,  grain,  and  small  animals.  It  also  swallows 
undigestible  matters,  such  as  stones,  which  probably  aid 

i  Fig.  293. 


308 


ZOOLOGY 


it  in  triturating  its  food.  The  nest  consists  of  a  hollow 
scooped  out  of  the  earth,  into  which  about  thirty  eggs  are 
laid.  Ostrich  feathers  are  used  for  ornament,  and  so 
important  is  the  commerce  in  these  articles  that  ostriches 


FIG.  293.  —  Apteryx  australis  with  egg.    From  a  specimen  in  the  Royal  College 
of  Surgeons,  London.    From  Parker  and  Haswell,  "  Text-book  of  Zoology." 

are  extensively  farmed  in  South  Africa.  When  reared  in. 
captivity  the  eggs  are  hatched  in  an  incubator,  and  the 
young  carefully  fed.  The  feathers  are  cut  off  and  not 
pulled  out,  so  that  the  operation  of  gathering  the  feathers 
is  a  painless  one. 


THE   ENGLISH   SPARROW  AND   ITS   ALLIES        309 

Bird  Migration.  —  The  birds  of  any  territory  may  be 
classified  on  the  basis  of  their  residence  into  four  groups  : 
permanent  residents,  winter  residents,  summer  residents, 
and  transient  visitants.  In  NCAV  York  the  permanent 
residents  are  represented  by  the  screech-owl,  the  crow, 
and  the  gold-finch.  Winter  visitants  are  represented  by 
the  snow-bird  and  white-throated  sparrow  ;  summer  resi- 
dents by  the  wood-thrush,  cat-bird,  yellow  warbler,  bobo- 
link, and  barn-swallow  ;  transient  visitants  by  most  of  the 
warblers,  the  fox-sparrow,  and  white-bellied  swallow.  As 
this  classification  indicates,  the  bird  fauna  of  any  place  is, 
to  a  great  extent,  shifting  from  season  to  season.  In  the 
spring  at  any  latitude  many  species  are  seen  passing  far 
north,  and  in  the  autumn  passing  south  again.  Tem- 
perate as  well  as  southern  latitudes  receive  in  the  winter 
time  the  southern  edge  of  a  more  northern  fauna.  Thus 
geese  and  ducks  are  forced  by  the  universal  ice  of  the 
Arctic  winter  to  go  to  regions  of  open  water,  at  least. 
Many  kinds  of  birds  which  spend  the  winter  in  the  South 
come  North  to  breed.  For  example,  the  bobolink  is  found 
nesting  in  the  New  England  fields  in  summer,  and  is  then 
altogether  absent  in  the  South.  In  the  fall  this  bird  is  not 
found  in  New  England,  but  occurs  in  the  Gulf  States  as 
the  rice-bird.  The  cause  of  this  migration  on  the  part  of 
birds  breeding  in  the  North  is  the  need  of  food.  Insectiv- 
orous birds,  especially,  could  not  obtain  food  enough  in 
the  North  in  winter. 

Migration  Routes.  —  It  is  known  that  many  species 
which  migrate  even  great  distances  travel  along  well- 
defined  paths.  In  Europe  the  paths  of  the  shore  migrants 
have  been  carefully  mapped  out.  It  appears  that  these 
birds  follow  the  shore  line  very  exactly,  except  in  some 


310  ZOOLOGY 

cases  in  which  it  can  be  demonstrated  that  their  paths  are 
along  ancient  shore  lines.  As  Wallace  says  :  "  It  is  easy 
to  see  how  the  migrations  that  had  once  taken  place  over 
continuous  land  would  be  kept  up  first  over  lagoons  and 
marshes,  then  over  a  narrow  channel,  and  subsequently 
over  a  considerable  sea,  no  one  generation  of  birds  ever 
perceiving  any  difference  in  the  route."  The  migration 
routes  of  North  America  have  not  been  well  studied.  The 
Atlantic  coast  is  one  line  ;  the  Mississippi  valley,  for- 
merly, no  doubt,  an  arm  of  the  sea,  is  another  route  along 
which  even  sea-birds  now  migrate.  The  question  how 
birds  recognize  and  are  able  to  follow  their  migration 
routes,  is  a  difficult  one  ;  they  seem  to  have  a  marvellous 
sense  of  direction.  There  is  great  need  of  a  more  perfect 
knowledge  of  migration  phenomena  in  North  America. 
Every  one  who  has  learned  to  distinguish  accurately  the 
species  of  birds  can  contribute  to  this  knowledge  by  keep- 
ing records  of  the  time  of  appearance  of  migrants  in  the 
spring  and  the  fall.  The  American  Ornithologists'  Union 
has  for  many  years  solicited  observations  on  this  subject 
from  voluntary  collaborators. 

Bird  Flight.  —  The  difficulties  which  must  be  overcome 
in  order  to  fit  birds  for  flight  are,  first,  that  of  sustaining 
the  heavy  body  in  a  medium  of  such  low  specific  gravity  as 
the  air  and,  secondly,  that  of  progression  in  this  medium. 
To  diminish  the  difficulty  of  sustaining  the  body,  the 
specific  .gravity  is  reduced  to  a  minimum  by  great  air- 
spaces in  the  body,  which  exist  even  in  the  hollow  bones.' 
The  body  is  kept  from  being  overturned  in  the  air  by  the 
position  of  the  wings,  which  are  placed  high  up  on  the 
trunk  while  the  digestive  organs,  breastbone,  and  breast 
muscles  are  placed  low.  To  aid  locomotion,  the  general 


THE  ENGLISH    SPARROW  AND  ITS   ALLIES       311 

form  of  the  body  is  made  conical,  so  as  to  offer  little  re- 
sistance to  the  air,  while,  by  varying  the  position  of  the 
head,  wings,  and  tail,  the  centre  of  gravity  is  quickly 
shifted.  In  starting  to  fly,  the  bird  gains  an  initial  veloc- 
ity, if  on  the  ground,  by  springing  into  the  air,  or  if  on  a 
tree,  by  combining  the  velocity  due  to  gravity  with  a  push- 
ing from  the  limb ;  but  aquatic  birds  strike  the  surface  of 
the  water  with  their  wings.  The  best  fliers  have  relatively 
large,  pointed  wings.  Three  methods  of  flight  are  em- 
ployed by  birds  when  once  in  the  air  :  (a)  stroking  the  air 
with  the  wing;  (£>)  gliding  or  skimming  ;  and  (c)  sailing  or 
soaring.  Some  birds  can  use  all  three  methods,  and  all 
good  fliers  use  the  first  two.  In  the  stroke  the  wing  moves 
downward  and  forward,  backward  and  upward,  so  that  the 
tip  of  the  wing  describes  a  OO ;  and  the  plane  of  the  wing 
constantly  changes  so  as  to  push  downward  against  the 
air,  and  thus  keep  the  bird  up,  and  to  push  backward 
against  the  air,  and  thus  drive  the  bird  forward.  At  the 
same  time,  the  wing  must  be  brought  back  to  its  upper  and 
anterior  position  without  offering  great  resistance  to  the 
air.  In  gliding,  the  wings  are  spread,  but  are  not  flapped, 
—  progression  depends  upon  an  acquired  velocity  or  upon 
the  wind.  In  soaring,  the  wings  remain  motionless,  and 
the  bird  does  not  lose  its  velocity  nor  tend  to  fall.  The 
way  in  which  the  bird  is  supported  and  carried  along  is 
uncertain.  It  seems  to  depend  upon  certain  favorable 
currents  in  the  air. 

Birds,  like  insects,  have  the  closest  economic  relations 
with  man.  A  few  of  them,  chiefly  belonging  to  the  orders 
of  Natatores  and  Gallinacei,  are  very  important  as  human 
food;  but  most  of  them  concern  man  on  account  of  their 
feeding  habits,  which  are  either  favorable  to  man,  as  when 


312  ZOOLOGY 

noxious  insects  are  destroyed  ;  or  injurious,  as  when  grain- 
fields  are  ravaged  or  other  birds  are  destroyed.  Un- 
questionably the  vast  majority  of  birds  are  commercially 
advantageous  to  man.  The  Rapt  ores  are  only  partially  so, 
for  they  feed  entirely  upon  animal  food,  chiefly  birds  and 
small  (usually  destructive)  mammals.  The  bobolink  and 
the  American  crow,  to  be  sure,  together  annually  destroy 
millions  of  dollars'  worth  of  grain,  yet  during  the  breeding 
season  they  both  feed  much  upon  insects.  Outside  of  the 
group  llaptores,  there  are  few,  if  any,  completely  noxious 
birds,  and  even  many  of  the  hawks  are  efficient  destroyers 
of  insects.  Legislation  directed  toward  the  destruction  of 
any  kind  of  birds,  excepting  the  English  sparrow  and  the 
Cooper's  and  sharp-shinned  hawk,  is  quite  as  apt  to  do 
harm  as  good. 

Bird  Protection.  —  Travellers  in  certain  parts  of  Europe, 
where  the  poverty  and  ignorance  of  the  people  have  led 
them  to  prey  upon  birds,  have  remarked  on  the  desolation 
of  a  birdless  country.  The  natural  enemies  of  insects 
being  destroyed,  there  is  no  adequate  check  to  the  destruc- 
tion of  vegetation  by  them  and  the  beauty  of  a  forest 
landscape  is  missing.  North  America  has  been  richly 
provided  witli  a  native  bird  fauna ;  but  within  the  last 
few  years  it  has  become  plain  that  most  of  our  species  are 
undergoing  reduction,  and  many  are  near  extermination. 
Careful  inquiries  recently  made  indicate  that  during  the 
past  fifteen  years  the  number  of  our  common  song-birds 
has  been  reduced  one-half,  and  the  number  of  certain  birds 
prized  as  food  or  ornament  has  been  reduced  to  one-fourth. 
At  the  present  rate,  extermination  of  many  species  will 
occur  during  the  lives  of  most  of  us.  The  causes  of  this 
destruction  of  birds  are  numerous.  The  most  efficient 


THE  ENGLISH  SPARROW  AND  ITS  ALLIES        313 

cause  is  the  shotgun  in  the  hands  of  boys  and  thoughtless 
men,  and  of  those  who  gather  birdskins  to  meet  the  demand 
for  bonnet  u  ornaments."  Very  great  destruction  is  also 
caused  by  egg-collectors,  who  annually  gather  scores  of 


FIG.  294.  —  Hesperornis  regalis.    The  restored  skeleton.    After  Marsh. 

thousands  of  eggs,  often  of  rare  birds.  The  disastrous 
results  of  killing  birds  need  only  to  be  appreciated  in 
order  to  put  a  stop  to  this  destructiveness. 

Extinct   Birds.  —  The   destruction  of    species  of   birds 
goes  on  fast  enough  without  the  more  efficient  aid  of  man. 


314 


ZOOLOGY 


We  know  of  species  which  have  become  extinct  within 
recent  times  through  the  introduction  of  new  enemies 
among  them.  Such  was  the  fate  of  the  dodo.  Then 
remains  have  been  preserved  to  us  in  the  rocks  of  species 
which  lived  in  very  remote  periods.  The  oldest  known 
fossil  bird,  ArchaDopteryx,  of  the  Jurassic  age,  had  a  long 
tail  like  a  lizard  ;  but  feathers,  which  are  only  modified 
scales,  were  present  even  in  this  oldest  known  bird.  In 
the  Cretaceous  rock  deposits  of  the  Great  Plains  there 
have  been  found  fossil  birds  with  teeth  set  in  sockets  or 
grooves,  precisely  as  they  are  to-day  in  reptiles  (Fig.  294). 
These  remains  show  us  in  the  clearest  manner  that  birds 
have  been  derived  from  reptiles.  Indeed,  the  two  groups 
are  closely  related  anatomically,  and  are  often  united 
under  the  name  Sauropsida  or  lizard-like  animals. 


APPENDIX   TO   CHAPTER   XIX 

KEY    TO    THE    ORDERS    OF    BIRDS 

a\.    Sternum  with  keel  for  insertion  of  flying  muscles 

[Carinatse]. 
bi.   Toes  more  or  less  webbed  or  fringed,  legs 

used  for  swimming  or  wading. 

c\.    Short  legs,  broadly  webbed  [Swimmers]  Natatores 

Ct.    Long  legs,  long,  thin  neck,  and  long  beak 

[Waders]     .      '  .        ....      .  .     '   ..  ,         Grallatores 

b%-    Feet  not  webbed,  fitted  for  walking, 
d-    With  cere. 

c?i.    Beak  strong,  and  bent  downward  at 

point ;  perching  feet ;  flat  nail       .  G-allinacei 

dz.  Beak  not  bent  downward  at  point-; 
short,  cloven  feet;  nail  com- 
pressed .....  Columbinw 


APPENDIX   TO   CHAPTER   XIX 


315 


d$.    Beak  hooked  ;  strong,  sharp,  hooked 

claws     ......  Eaptores 

d±.    Beak  shorter  than  high  ;  thick,  fleshy 

tongue   .        .        .  -...'.  Psittaci 

C2.    Without  cere. 

d±.    Beak  long,  often  heavy  ;  tongue  thin ; 

stiff    plumage   with    little  down ; 

metatarsus    with    half    rings    on 

scutes;  feet  scansorial        .        .        .         Scansores 
d%.    Metatarsus  with  no  scales  or  rudi- 
mentary ones  ;  feathered  in  upper 

part       .        .        .  .        .     Cypselomorphce 

t?3.    Metatarsus  covered  with  laminae  or 

scales,    rarely    feathered,    usually 

with  singing  apparatus  ;   feet  not 

scansorial,  mostly  migratory        .;.  Passeres 

Sternum  without  keel  [Ratitse]    .        .  ..  ...*       .  Cursores 


KEY    TO    THE    FAMILIES    OF    PASSERES    OF    NORTHERN     UNITED 
STATES,    BASED    ON    D.    S.    JORDAN 

«i.   First  of  the  10  primaries  more  than  f  length  of 

longest  of  the  others  [Clamatores]    .        .        .  Tyraimidce 

«2-  First  of  10  primaries  short,  rudimentary  or  ab- 
sent ;  musical  apparatus  highly  developed 
[Oscines]. 

61.  First  primary  short  or  spurious  [primaries  10]. 
Ci.    Tarsus  booted  ;  rictus  with  bristles. 

d\.    Middle  toe  quite  free  from   inner ; 
birds    of    moderate    size ;    length 
more  than   15  centimetres. 
e\.    Wings  when  folded  not  reaching 

beyond  middle  of  tail ;  no  blue  Turdidce 

•    e%.    Wings  reaching  beyond  middle 

of  tail ;  ours  chiefly  blue         .  Saxicolidce 

c?2-    Middle  and  inner  toe  connected  at 
base ;    length    less   than    13   cen- 
timetres        .  •„        ,        .  Sy1viid.ce 
c2.    Tarsus  scutellate  in  front. 

d\.   Nostrils  concealed  by  bristly  feathers. 


316 


ZOOLOGY 


ci.   First  primary  not  more  than  £ 
length  of  second  ;  length  less 
than  20  centimetres. 
/i.    Bill  as  long  as  head ;  wings 

longer  than  tail          .         .  tiittidte 

/2.    Bill  much  shorter  than  head  ; 

wings  about  as  long  as  tail  Paridas 

e%.  First  primary  more  than  \  lengtli 
of  second  j  length  more  than 
20  centimetres  .  .  ,  :  Corvtdce 

d2-    Nostrils  exposed  or  merely  overhung 

by  feathers, 
ci.    Bill  notched  near  tip. 

/i.  Tail  longer  than  wings  ;  gen- 
eral color  gray  or  ashy 
brown. 

g\.    Bill  very  stout  and  deeply 
notched  and  hooked  ; 
bird    over    17    centi- 
metres        .     ';'„.        .  Laniidce 
f/o.    Bill     neither     stout, 
notched,  nor  hooked  ; 
bird  over  17  centimetres                Turdidce 
<jz.    Bill   very  slender ;   bird 

under  17  centimetres  .  /Sylviidcu 

fa.    Tail  shorter  than  wings ;  gen- 
eral color  olivaceous .        -,  Vireonidai 
P.Z.    Bill  not  notched. 

fr    Rictus  with  bristles. 

~y\.    Quills  not  barred  ;  length 

over  20  centimetres    .  Turdidw 

y-2.   Wing  and  tall    barred ; 
length  under   18  cen- 
timetres     .         ...         Troglodytidce 
/2.    Rictus  without  bristles         .  Certhiidte 

First  primary  about  as  long  as  second  ;  the 
real  first  rudimentary,  leaving  apparently  9. 
c,.    Bill  triangular,  depressed,  as  wide  at  base 

as  long  ;  gape  twice  as  long  as  culmen  Hir-udinidas 

c2.    Bill  stout,  conic,  with  convex  outlines, 


APPENDIX  TO   CHAPTER  XIX 


817 


edge  of  upper  bill  with  lobes  or  nicks 

near  middle Tanagridce 

Bill   conical,    corners   of    mouth   drawn 

down. 

d\.    Bill  much  shorter  than  head,  usually 
notched  at  tip  or  with  bristles  at 
rictus     ......  Fringillidce 

d-2.    Bill  usually  about  as  long  as  head  ; 

no  notch  at  tip  nor  bristles  at  rictus  Icteridw 

Bill  not  as  above ;    edge   of  upper  bill 

straight  or  very  gently  curved. 
d\.    Conspicuously    crested ;    bill    trian- 
gular,   depressed,    notched,    and 
hooked ;  tail  tipped  with  yellow  ; 
wings  red-tipped    ....  Ampeliilw 

d-2.    Nostrils  concealed   by  bristly  feath- 
ers; tarsus  scutillate  behind .        V  Al«.wlhl<v 
ds.    No  crest ;    nostrils  exposed  ;    tarsus 
with  sharp  ridge  behind  formed  of 
union  of  two  lateral  plates. 
e\.    Hind  claw  twice  as  long  as  mid- 
dle claw  .        .        .    '  -.    _  .   .       MotatiUid<K 
f>2.    Hind  claw  not  twice  as  long  as 

middle  claw. 

/i.  Bill  stout,  compressed,  hooked 
at  tip  ;  tail  not  blotch*  d 
with  red  or  yellowr  .  •  .  •-  Vireonnlie 

/2.  Bill  various ;  little,  if  at  all, 
hooked  ;  colors  often  brill- 
iant .  ....  .  Sylvicolidct 


CHAPTER   XX 

THE   MOUSE   AND   ITS   ALLIES 

THE  mouse  belongs  to  the  class  Mammalia,1  character- 
ized by  having  milk  glands  whose  secretion  is  used  to 
nourish  the  young,  and  hair,  which  may  be  nearly  or 
quite  absent  as  in  the  case  of  porpoises  or  whales.2 

The  distribution  of  the  house  mouse,  from  which  the 
different  kinds  of  fancy  mice  have  been  derived,  is  now  co- 
incident with  that  of  civilized  man ;  but  in  early  times  it 
was  limited  to  Asia.  From  Asia  it  made  its  way  to  Europe, 
and  thence  by  vessels  to  other  continents.  It  was  imported 
to  America  (which  has  no  indigenous  members  of  the  genus 
Mus)  by  the  early  explorers.  There  have  also  been  im- 
ported to  this  country  three  other  species  of  this  genus,  of 
such  size  that  they  are  commonly  called  rats.  Of  these, 
the  roof  rat  seems  to  have  been  imported  by  the  early 
Spanish  discoverers  to  the  Southern  States,  where  it  still 
persists.  It  originated  in  Egypt.  The  second  was  the 
black  rat,  believed  to  have  been  imported  to  America  about 
1544.  It  has  existed  from  time  immemorial  in  Europe  ;  it 
has  a  mild  disposition,  and  from  it  the  white  rats  we  keep 
as  pets  have  been  derived.  The  brown,  or  Norway  rat, 
has  been  the  latest  importation.  The  history  of  its  migra- 
tions has  been  written.  Probably  originating  in  central 

1  mammalis,  belonging  to  the  breast. 

2  A  key  to  the  orders  of  Mammalia  will  be  found  in  the  Appendix  to 
this  Chapter,  page  331. 

318 


THE  MOUSE  AND   ITS  ALLIES  319 

Asia,  it  crossed  the  Volga  hi  great  troops  in  1727,  occupied 
Russia  in  173Q,  France  in  1750,  and  Denmark  about  1810. 
Before  the  advance  of  this  powerful  and  aggressive  foe, 
the  black  rat  of  Europe  gave  way,  and  became  Avell-nigh 
exterminated,  although  of  late  it  is  said  to  be  reasserting 
itself  in  Germany.  The  brown  rat  was  introduced  into 
America  in  1775,  has  spread  over  the  whole  country, 
reaching  the  Pacific  coast  about  1855,  and,  as  in  Europe, 
has  nearly  exterminated  the  black  rat. 

The  habits  of  rats  and  mice  are  well  known.  They 
inhabit  our  buildings,  gnaw  our  doors  and  furniture,  de- 
stroy our  provisions,  kill  poultry,  and  aid  in  spreading 
disease.  They  shun  the  light,  living  in  holes  during  the 
day,  run  with  great  agilit}^  and  are  capable  of  making 
long  leaps.  Owing  to  their  instinct  to  go  into  holes,  they 
are  easily  trapped  by  a  funnel-shaped  opening  leading  into 
a  closed  box.  Despite  the  ease  of  trapping  and  their 
destruction  by  cats,  they  maintain  themselves  by  virtue  of 
a  great  fecundity,  for,  if  no  deaths  occur,  several  hundred 
young  may,  in  one  year,  descend  from  a  single  pair. 

The  food  of  mice  is  very  varied.  They  naturally  thrive 
best  on  a  vegetable  diet;  oats  especially  are  recommended 
for  tame  mice,  and  hard-shelled  nuts  are  useful  because 
the  mice  keep  their  teeth  sharp  by  gnawing  the  shells.  If 
the  teeth  are  not  kept  worn  off  they  soon  become  incon- 
veniently long  owing  to  the  fact  that  they  grow  continu- 
ously throughout  life,  and  are  not  formed,  once  for  all,  like 
our  teeth.  In  addition  to  plant  materials,  rats  and  mice 
eat  a  certain  amount  of  animal  food. 

The  different  races  of  tame  mice  illustrate  the  results 
obtained  by  preserving  sports  and  selecting  the  best  for 
breeding  purposes.  The  white  mouse,  for  instance,  is  an 


320  ZOOLO<;  r 

albino  ;  that  is,  an  animal  without  pigment.  Albinos  oc- 
cur among  almost  all  kinds  of  mammals,  but  the  cause  of 
them  is  unknown.  So,  likewise,  the  black  race  of  tame 
mice  is  due  to  an  excess  of  pigment,  a  sport  found  now 
and  then  among  other  mammals.  The  pure  reddish  brown 
races  have  probably  been  produced  by  selecting  the  house 
mice  with  little  black  in  the  fur.  By  preserving  occasional 
sports  and  by  selecting  for  breeding  the  purest-colored 
individuals,  all  the  different  races  of  our  domestic  animals 
and  plants  have  been  established  and  improved. 
.  Other  Rodents.  —  The  mouse  belongs  to  the  group  Ro- 
dentia,1  distinguished  from  other  mammals  by  the  fact  that 


FIG.  295.  —  Geomys  tuza,  the  Georgia  gopher.     One-half  nat.  size.     After 
V.  Bailey. 

the  cutting  teeth  grow  continuously  throughout  life,  a  con- 
dition associated  with  the  habit  of  gnawing.  This  group 
is  very  abundantly  represented  in  North  America,  more 
so,  indeed,  than  in  other  continents.  All  our  rodents  fall 
into  seven  families:  (1)  the  squirrels,  gophers  (Fig.  295), 
prairie  dogs,  and  woodchuck,  with  long  and  hairy  tail; 
(2)  the  beaver,  with  broad  and  scaly  tail ;  (3)  the  pouched 
gophers,  with  peculiar  cheek  pouches  opening  outside  the 

1  From  rodere,  to  gnaw. 


THE  MOUSE  AND  ITS  ALLIES  321 

mouth;  (4)  the  jumping  mice,  with  greatly  elongated 
hind  legs;  (5)  the  muskrat  and  the  various  wood  and 
field  mice,  closely  related  to  the  genus  Mus  ;  (6)  the  por- 
cupines, with  bristles  replacing  hairs ;  (7)  the  hares,  with 
long  ears  and  short  tails.  All  of  these  familiar  rodents 
are,  on  the  whole,  destructive  to  agriculture.  As  there 
are,  however,  other  interests  in  life  than  agriculture,  it  is  to 
be  hoped  that  the  warfare  against  our  native  rodents  will 
not  be  too  relentlessly  pursued.  At  least  one  interest- 
ing species  has  been  rendered  well-nigh  extinct  by  the 


FIG.  296.  —  Ornithorkyncnus  anatmus,  the  duckbill.      After  Vogt  and  Specht. 

avarice  of  fur  hunters  —  this  is  the  American  beaver,  an 
animal  which  has  developed  extraordinary  instincts  for  the 
construction  of  dams  and  subaquatic  passages. 

Other  Mammals.  —  The  Monotremata1  are  the  lowest 
mammals,  and  in  many  ways  seem  to  connect  the  class 
with  reptiles  or  amphibians.  The  milk  glands  are  in  a 


s,  single,  r/o^a,  hole  or  opening  ;  so  called  because  urinary,  geni- 
tal, and  alimentary  canals  have  a  common  external  opening. 

Y 


822  ZOOLOGY 

low  state  of  development  and  eggs  are  laid,  as  in  reptiles 
and  birds.  There  are  two  principal  types,  —  the  "Duck- 
bill "  (Fig.  296),  with  aquatic  habits,  and  the  "  Spiny 
Ant-eaters  "  (Echidna,  Fig.  297),  inhabiting  rocky  places. 
Both  types  are  confined  to  Australia  and  neighboring 
islands. 

The  Marsupialia l  have  a  remarkable  distribution  over 
the  earth  to-day.     All  are  confined  to  Australia  and  adja- 


FIG.  297.  —  Echidna  aculeata,  the  spiny  ant-eater.    After  Vogt  and  Specht. 

cent  islands,  excepting  the  family  of  opossums  (Fig.  298), 
found  only  in  the  Americas.  There  is  thus  a  great  dis- 
continuity in  the  distribution  of  marsupials.  This  is 
accounted  for  by  the  evidence  that  formerly  the  whole 
world  contained  marsupials,  so  that  those  living  to-day  are 
the  separated  remnants  of  that  once  universal  race.  The 
opossums  are  most  numerous  in  the  tropics,  but  the  Vir- 
ginian opossum  ranges  north  to  New  York. 
1  marsiiphim,  a  pouch. 


THE  MOUSE  AND  ITS  ALLIES  323 

The  Edentata,1  few  of  which  are  entirely  without  teeth, 
include  the  sloths,  hairy  ant-eaters,  armadillos,  scaly  ant- 
eaters,  and  aardvarks,  or  African  ant-eaters.  The  three 
first-named  families  inhabit  South  America ;  the  two 
latter,  Asia  and  Africa.  Here,  again,  the  discontinuity  of 
the  group  indicates  what  fossils  prove,  that  the  Edentates 


FIG.  298.  —  Didelphys  virginiana,  the  North  American  opossum.    After 
Vogt  anrd  Specht. 


have  been  killed  off  from  the  connecting  continents.  The 
sloths  have  incisor  teeth,  live  in  trees,  and  eat  leaves  (Fig. 
299).  The  armadillos  are  protected  by  strong  plates  de- 
veloped in  the  skin  ;  they  are  chiefly  nocturnal  and  om- 
nivorous animals,  and  burrow  rapidly.  The  other  three 
families  feed  on  ants  and  termites,  lack  complete  teeth  (ex- 
cepting the  aardvarks),  and  are  either  arboreal  or  burrowing. 

1  e,  out ;  dens,  dentis,  tooth. 


324  ZOOLOGY 

The  Cetacea1  have  taken  to  an  aquatic  life,  for  it  is 
certain  that  their  ancestors  were  land  animals.  The  sea- 
cows  (manatees2),  found  in  rivers  in  various  parts  of  the 
world,  seem3  to  show  a  transition  to  the  marine  forms, 


FIG.  299.  —  Choloepus,  the  unau  or  two-toed  sloth.    After  Vogt  and  Specht. 

such  as  the  dolphins,  the  toothed  whales  (Fig.  300), 
and  the  toothless  or  whalebone  whales.  The  largest  of 
these  whales  —  the  Greenland  whale  —  reaches  an  ex- 
treme length  of  twenty-two  to  twenty-four  metres,  and  a 

1  cetus,  whale.  2  From  a  native  name. 

3  The  relation  to  Cetacea  is  not  close. 


THE  MOUSE  AND  ITS  ALLIES  325 

weight  of  over  100,000  kilogrammes.  It  is,  indeed,  the 
largest  living  animal.  Although  whales  in  general  are 
partly  adapted  to  an  aquatic  life,  they  still  retain  the 
essential  mammalian  qualities.  They  breathe  air  which 
passes  to  the  lungs  and  is  expelled  again  through  the 
nostrils,  which  are  placed  high  up  on  the  head.  The 
"  blowing "  of  the  whale  is  the  forcible  expiration  of 
moisture-laden  air,  which  becomes  visible  by  condensation, 


. 

ttb. 


"  ~  _ 

_ 

FIG.  300.  —  Orca,  the  killer  whale.    After  True. 

just  as  our  own  breath  does  on  a  cold  day.  The  young 
are  doubtless  born  in  the  water,  but  the  breeding  habits 
are  poorly  known.  The  various  Cetacea  have  diverse 
feeding  habits.  All  are  predaceous.  The  toothed  whales 
feed  on  larger  animals,  the  whalebone  whales  on  floating 
fish,  Crustacea,  medusae,  and  squids  ;  their  whalebone  is, 
indeed,  merely  a  strainer  to  let  the  water  pass  out  of  the 
mouth  while  the  solid  masses  are  retained. 

The  order  Ungulata1  includes  a  large  number  of  animals, 

1  unyula,  hoof. 


326 


ZOOLOGY 


almost  all  of  which  are  closely  related.  In  the  true  ungu- 
lates there  are  never  more  than  four  functional  toes ;  but 
in  the  subgroup  of  Subungulata,  containing  the  elephants 
and  certain  small  animals  allied  to  the  "coney"  of 
Scripture,  there  are  typically  five.  Of  the  true  ungulates, 
we  distinguish  the  even-toed  and  the  odd-toed,  which  we 
may  consider  further. 


m 


FIG.  301.  —  Stone's  Alaskan  black  sheep.    Photo,  of  a  group  m  the  Field 
Columbian  Museum. 

The  Even-toed  Ungulates  include  the  hippopotamus  and 
other  pigs  and  the  peccaries,  the  camels  and  llamas,  the 
deer,  the  giraffes,  and  the  antelopes,  sheep  (Fig.  301),  and 
oxen.  Excepting  the  pigs,  most  of  these  feed  exclusively 
on  plants.  The  giraffes  and  antelopes  are  characteristic  of 
Africa ;  but  the  "  mountain  goat "  of  our  highest  ranges  is 


THE  MOUSE  AND  ITS  ALLIES  327 

a  true  antelope,  as  is  also  the  chamois  of  Europe.  The 
prong-horn  of  our  Southwestern  plains  is  remarkable  in 
having  hollow  horns  like  the  antelopes,  which  are,  how- 
ever, shed  like  those  of  the  deer. 

The  Odd-toed  Ungulates  include  the  horses,  tapirs,  and 
rhinoceroses.  The  horses  are  remarkable  in  that  they  stand 
upon  the  toe-nail  of  the  middle  digit  —  all  the  other  digits 
being  rudimentary  or  absent.  While  fossil  remains  of 
horses  are  found  in  all  continents,  the  living  species  have 
come  from  Asia  and  Africa.  The  African  species  are 
striped  (zebras).  The  tapirs  are  found  living  to-day 
only  in  South  America  and  southeastern  Asia.  They 
frequent  the  depths  of  forests  near  watercourses  and 
feed  on  leaves  and  shoots  of  shrubbery.  The  rhinoceroses 
of  Africa,  of  India,  of  Java,  and  of  the  Malay  Archipelago 
are  quite  distinct.  All  are  large,  stupid,  and  ferocious 
when  attacked,  feed  on  herbage,  and  wallow  in  pools. 

The  elephants  are  distinguished  by  their  long  trunks, 
great  incisors  (tusks),  and  huge,  complex  grinding  teeth. 
The  Indian  and  African  types  are  quite  distinct.  Ele- 
phants are  intelligent,  tractable,  and  capable  of  doing 
much  work  for  man.  Their  diet  is  vegetable,  consisting 
especially  of  the  leaves  and  young  branches  of  forest 
trees,  which  they  gather  with  their  proboscis. 

The  Insectivora1  are  small  mammals  and  chiefly  terres- 
trial. One  of  our  common  families  includes  species  of 
moles  which  burrow  in  the  ground,  have  small  eyes  and 
broad,  shovel -shaped  fore  feet,  used  for  digging  their  bur- 
rows. They  feed  chiefly  on  earthworms.  The  other 
common  family  is  that  of  the  shrews,  which  are  mouse-like, 
live  chiefly  on  the  surface  and  in  the  woods,  and  feed  on 
insects  and  small  crustaceans. 

1  insectum,  an  insect ;  vorare,  to  devour. 


328 


ZOOLOGY 


The  Carnivora1  include  both  land  and  marine  forms. 
To  the  first  group  (Fig.  302)  belong  the  cats  (including 
tigers,  lions,  leopards,  lynx,  etc.)  ;  the  civet-cats,  mongoose, 


FIG.  302.  —  Felis  jubata,  the  Cheetah  or  hunting  leopard.    Photo,  of  a  group, 
in  the  Field  Columbian  Museum. 

etc. ;  the  hyenas  ;  the  dogs  (including  jackals,  wolves,  and 
foxes) ;  the  bears;  the  raccoons;  and  the  great  fur-bearers, — 
martens,  minks,  weasels,  badgers  and  otters,  and  skunks. 


FIG.  303.  —  Phoca  vitulina,  the  harbor  seal.    From  Parker  and  Has  well, 
"  Manual  of  Zoology." 

1  caro,  carnis,  flesh  ;  vorare,  to  devour. 


THE  MOUSE  AND  ITS  ALLIES  329 

Marine  Carnivora  comprise  the  seals  (Fig.  303),  walruses, 
and  sea-lions ;  the  more  valuable  of  which  are  disappearing 
as  a  result  of  man's  lack  of  foresight.  Altogether,  the  Car- 
nivora comprise  the  most  agile,  the  most  intelligent,  the 
most  dreadful,  and  some  of  the  commercially  most  im- 
portant of  fellow-animals. 

The  Cheiroptera,1  or  bats  (Fig.  304),  are  extraordinarily 
modified   mammals,  which,  like  the  birds,  seem  to  have 


FIG.  304.  —  Synotus,  an  insectivorous  bat.    After  Vogt  and  Specht. 

penetrated  into  the  air  to  prey  on  the  flying  insects.  Not 
all  bats  are  insectivorous,  however,  for  certain  Old  World 
bats  feed  on  fruits.  Our  commonest  species  are  the  little 
brown  bats  (with  a  nearly  furless  wing),  and  the  red  bat 
(with  patches  of  fur  on  the  wing  membrane). 

The  Primates2  are  of  interest  because  we  ourselves  are 
placed  in  this  category  together  with  certain  other  animals 
that  have  attained  a  less  lofty  station.  The  lowest  Pri- 
mates are  the  lemurs,  found  chiefly  in  Madagascar.  These 
have  an  arboreal  habit,  and  feed  on  fruits,  leaves,  and 

1  xfLpi  hand ;  Trre/^p,  wing.  2  primus,  the  first. 


330 


ZOOLOGY 


small  birds  and  insects.  Next  higher  come  the  American 
marmosets,  the  howling  monkeys,  and  the  flat-nosed,  pre- 
hensile-tailed American  apes;  still  higher  are  the  small- 
nosed,  nonprehensile-tailed  apes,  including  the  baboons, 


FIG.    305.  —  Simla    satyt^us,   the  orang-utan,   in   breadfruit   tree.      From  a 
photograph  of  a  group,  in  the  Field  Columbian  Museum. 


mandrills,  and  macaques.  Finally,  come  the  tailless,  man- 
like apes,  found  exclusively  in  the  Old  World  —  the  gib- 
bons, orangs  (Fig.  305),  chimpanzee,  and  the  gorilla. 
The  two  latter  are  nearest  to  man,  but  one  cannot  say 
one  is  the  nearer.  For,  while  the  chimpanzee  approaches 


THE  MOUSE  AND  ITS  ALLIES  331 

man  more  closely  in  facial  appearance  and  in  intelligence, 
the  gorilla  is  more  man-like  in  the  size  and  complexity  of 
the  brain  and  in  its  habit  of  walking  on  the  ground.  There 
is  no  reason  to  doubt  that  man's  species  came  off  from  the 
anthropoid  apes  ;  the  recent  discovery,  in  Java,  of  a  fossil 
form  (Pithecanthropus  erectus)  intermediate  between  man 
and  the  man-like  apes,  is  a  strong  additional  piece  of  evi- 
dence. This  differentiation  of  man's  species  probably 
began  in  late  tertiary  times. 


APPENDIX    TO    CHAPTER     XX 

KEY    TO    THE    ORDERS    OF    MAMMALIA 

Oviparous;  no  mammae  developed  .  .  .  Monotremata 
Young  born  prematurely  ;  reared  in  marsupium  .  Marsupalia 
Viviparous  ;  no  marsupium. 

hi.     Teeth  without  enamel      .         .         .  .  Edentata 

b-2-     Teeth  with  enamel. 
ci.     Hind  limbs  absent. 

<?i.     Elbow  and  wrist  move  on  each  other  tSirenia 

(Z2.     Fore  limbs  not  flexible      i        '.."    -   ..  Cetacea 

c%.     Hind  limbs  present. 

di.     Digits  end  in  hoofs  or  hoof-like  nails  Ungulata 

d%.     Digits  end  in  claws. 

e\.     Without  hands   or  membranes 

between  digits. 

/i.     Canines  absent   .  .  Eodentia 

ft.     Canines  large      .        .        .          Carnivora 
/3.     Canines  small     .         .         .         Insectivora 
e^.     Without  hands ;  membrane  be- 
tween digits   ....        Cheiroptera 
e&.     With  hands       ....  Primates 


CHAPTER  XXI 

THE  DEVELOPMENT  OF  THE  FROG'S  EGG 

ALL  living  matter  has  the  capacity  of  increasing  itself 
under  proper  conditions  to  an  almost  unlimited  extent, 
the  food  which  animals  devour  being  the  material  out  of 
which  the  new  living  substance  is  made.  This  living  sub- 
stance exists  in  isolated  particles,  or  masses,  which  we  call 
individual  animals  or  plants.  The  animal  or  plant  has 
also  at  any  stage  a  definite  form  which  is  not  exactly  alike 
in  any  two  individuals,  but  is  roughly  alike  inside  the 
"species."  Now  the  number  of  individuals  of  any  species 
tends  constantly  to  diminish  through  death.  It  is  actually 
maintained  by  reproduction.  Reproduction  always  takes 
place  in  one  way;  namely,  by  a  piece  of  the  parent 
individual  being  cut  off  to  form  a  new  individual.  This 
piece  may  be  at  first  almost  shapeless  or  approximately 
spherical.  Bat  as  it  grows  larger  it  assumes  more  and 
more  the  form  and  complex  structure  of  the  adult.  This 
process  of  growing  into  the  adult  form  is  development. 
In  most  of  the  more  familiar  cases  development  begins 
with  an  approximately  spherical  egg. 

In  the  case  of  the  frog,  the  egg  is  between  one  and  two 
millimetres  in  diameter.  The  eggs,  which  are  numerous, 
are  laid  in  a  common  jelly  and  during  development  float 
near  the  surface  of  the  water  in  which  they  are  laid. 

332 


THE  DEVELOPMENT  OF  THE  FROG'S  EGG         333 

Effect  of  Heat  and  Light  on  Development.  —  Eggs  devel- 
oping in  normal  environments  in  nature  arrive  at  nearly 
the  same  end-result  even  when  the  environments  are  not 


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60°FAHR..                  56°FAHR.                  53°FAHR.                 51°FAHR. 

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FIG.  306.  — A  chart  showing  the  correlation  between  the  stage  of  development 
of  the  frog  on  successive  days  and  the  temperature  at  which  it  has  de- 
veloped. From  Higgenbottom. 

identical.  We  gain,  in  consequence,  an  impression  that 
development  proceeds  unaffected  by  any  changes  in  the 
outside  world.  But  this  is  not  true.  For  one  thing,  the 


334  ZOOLOGY 

rate  at  which  the  development  of  frogs'  eggs  proceeds  de- 
pends closely  upon  the  temperature  of  the  water.  They 
develop  most  rapidly  at  about  30-32°  C.  If  the  tempera- 
ture is  elevated  above  this  point,  the  rate  of  development 
is  retarded,  and  finally  ceases  at  about  40°  C.  So,  likewise, 
as  the  temperature  is  lowered,  the  development  is  retarded, 
until  at  the  temperature  of  freezing  water  it  ceases 
(Fig.  306).  If  the  temperature  is  too  high,  development 
may  be  abnormal,  so  that  a  monstrosity  is  produced. 

Light  has  a  less  striking  effect  on  the  development  of 
the  frog.  If  light  is  excluded  from  the  developing  eggs, 
they  will  develop  more  slowly.  The  acceleration  of 
development  by  rather  high  temperature  and  by  daylight 
is  probably  due  to  a  chemical  effect  of  these  agents.  It 
indicates  that  development  is  a  complex  chemical  process. 

Healing  and  Regeneration.  —  If  the  egg  of  a  frog  be 
pricked  slightly,  there  will  be  a  loss  of  substance  and  the 
resulting  embryo  will  be  at  first  abnormal.  Later,  how- 
ever, this  abnormality  will  become  smoothed  over  by 
appropriate  development.  So,  also,  if  the  tail  of  the 
developing  larva  is  mutilated,  the  wound  will  heal  and  the 
missing  parts  will  be  re-formed.  This  capacity  of  the  living 
organism  to  restore  the  normal  form  after  mutilation  is 
seen  also  in  man.  For  if  some  of  the  skin  be  cut  away,  or 
even  if  parts  of  internal  organs  are  removed,  the  wounds 
will  not  merely  heal,  but  the  lost  part  will  regenerate. 
The  remarkable  thing  is  that  in  regeneration  almost 
exactly  that  is  produced  which  was  lost.  Both  regenera- 
tion and  healing  in  the  adult  are  a  survival  of  the  same 
capacity  for  development  which  we  see  in  the  egg. 

Postembryonic  Development  of  the  Frog.  —  After  reach- 
ing a  certain  stage  of  development  the  embryo  frog,  called 


THE  DEVELOPMENT  OF  THE  FROG'S   EGG         335 

tadpole,  begins  to  develop  legs.  The  hind  legs  first 
appear,  afterward  the  fore  legs  sprout  out,  and  finally 
the  tail  begins  to  wither  away,  until  the  form  of  the  four- 
legged  tailless  frog  (anuran)  is  fully  developed.  In  the 
leopard  frog,  as  in  the  toad,  this  change  of  form  (metamor- 
phosis) is  completed  during  the  first  summer,  but  in  case 
of  the  bullfrog  and  green  frog  the  tadpole  passes  through 
the  winter  in  the  immature  state,  and  does  not  complete 
its  metamorphosis  until  the  second  summer.  Conse- 
quently, it  is  not  uncommon  to  find  quantities  of  large 
tadpoles  in  ponds  at  the  time  the  ice  breaks  up  in  the 
spring. 

Since  Amblystoma  and  Necturus  do  not  lose  their  tails, 
the  metamorphosis  which  they  undergo  is  less  profound 
than  that  of  the  frog.  In  Amblystoma,  as  stated  in  Chap- 
ter XVII.,  the  gills  and  the  fin  on  the  tail  of  the  tadpole 
are  lost  in  the  metamorphosis.  Necturus,  on  the  con- 
trary, retains  gills  and  tail-fin,  so  that  its  acquisition  of 
legs  is  almost  the  sole  indication  of  metamorphosis. 

General  Laws  of  Development.  —  Development  consists 
of  an  unfolding  of  potentialities  wrapped  up  in  the  germ  ; 
an  awakening  in  orderly  succession  of  processes  lying 
dormant  there.  But  the  causes  which  control  develop- 
ment, the  causes  which  determine  when  this  process  and 
that  shall  awaken,  are  still  too  obscure  for  us  to  attempt 
to  picture  them  in  detail.  This  much  is  certain,  that  the 
causes  of  development  from  the  egg  are  the  same  as  those 
of  budding  of  leaves  on  a  tree,  the  regeneration  of  the 
parts  of  a  Hydra,  or  the  healing  of  a  cut  in  the  skin.  In 
the  case  of  most  of  the  higher  plants  and  animals,  the  ripe 
egg  will  not  develop  until  it  is  "  fertilized,"  that  is,  until  a 
germ  from  another  individual  has  fused  with  the  ripe  egg. 


336  ZOOLOGY 

But  the  ripe  egg  of  many  of  the  lower  plants  and  animals 
requires  no  fertilization  for  development,  and  the  meaning 
of  the  fertilization  process  is  quite  obscure. 

The  developing  eggs  of  all  the  higher  animals  pass 
through  much  the  same  sort  of  early  stages.  The  egg 
"  cleaves "  into  a  number  of  cleavage  spheres,  each  of 
which  is  destined  to  give  rise  to  a  particular  part  of  the 
organism.  By  repeated  division,  a  mass  of  small  cells, 
constituting  the  morula  stage,  is  formed.  Usually  a 
cavity  arises  in  the  middle  of  the  morula,  and  into  this 
some  of  the  surface  cells  are  pushed  to  form  an  internal 
sac  —  the  food  canal.  This  is  necessarily  an  early  step,  as 
all  food  is  taken  into  the  interior  of  the  body.  The  pro- 
cess by  which  external  cells  are  pushed  in  is  known  as 
gastrulation.  Very  early  the  body  is  seen  to  be  composed 
mostly  of  layers,  or  membranes  and  cavities.  It  is  by  the 
folding  and  union  and  breaking  through  of  these  mem- 
branes that  most  of  the  organs  of  the  adult  arise.  Devel- 
opment of  the  individual  is,  on  the  whole,  accompanied 
by  increase  in  complexity.  The  evolution  of  animals  in 
the  animal  kingdom  is  likewise,  on  the  whole,  accompanied 
by  increase  in  complexity  of  organization.  Thus  both  the 
embryonic  development  of  the  individual  and  the  evolu- 
tion of  the  species  proceed  from  simple  to  complex,  and 
since  they  start  from  about  the  same  point  and  reach  the 
same  goal,  we  are  not  surprised  to  find  that  the  individual 
development  of  any  species  often  goes  through  stages 
markedly  like  the  stages  in  the  evolution  of  the  species. 
The  parallelism  of  development  and  evolution  was  early 
noticed,  and  is  often  called  "  von  Baer's  law,"  after  a 
naturalist  who  lived  in  the  middle  of  the  nineteenth  cen- 
tury and  very  clearly  formulated  this  parallelism. 


APPENDIX  I 

NOTE. —  This  outline  is  reprinted,  with  some  changes  suggested  by  putting  it 
in  practice,  and  with  the  addition  of  Exercise  XX.,  from  an  "  Outline  of 
Requirements  in  Zoology  intended  for  use  in  preparing  students  for  the 
Lawrence  Scientific  School,"  Harvard  University,  published  in  1898  by  the 
University.  The  outline  was  the  product  of  the  Zoological  Department 
of  the  University,  waft  planned  in  detail  by  one  of  the  present  writers,  and 
is  republished  by  permission  of  the  University.  The  outline  agrees  also 
with  the  requirements  for  admission  in  Zoology  to  the  University  of  Chi- 
cago, and  with  the  recommendations  of  the  sub-committee  of  ten  on 
Zoology  appointed  by  the  National  Educational  Association.  Its  general 
plan  has  been  followed  in  various  schools  over  the  country.  The  favor- 
able reception  of  the  outline  justifies  its  reproduction  here. 

OUTLINE   OF  LABORATORY  WORK   IN   ZOOLOGY 
INTRODUCTION1 

Time.  —  This  outline  of  work  in  Zoology  is  designed  for  use  in 
schools  that  can  give  to  the  subject  five  periods  per  week  for  half 
a  year,  including  time  spent  in  laboratory  work,  written  exercises, 
and  oral  instruction  by  the  teacher.  It  is  likewise  available  for 
schools  that  follow  the  recommendation  of  the  Committee  of  Ten 
of  the  National  Educational  Association  and  give  to  the  subject 
three  periods  per  week  throughout  the  year. 

Amount  of  work.  —  The  outline  includes  much  more  work  than 
any  school  ought  to  attempt  in  the  time  indicated  above.  It  is 
believed  that  if  about  ten  of  the  twenty-one  exercises  are  thoroughly 
done,  the  time  will  be  well  filled.  The  number  of  exercises  is  made 
large  to  admit  of  a  selection  to  suit  the  diverse  conditions  of  schools. 
Thus,  those  schools  which  are  not  equipped  with  compound  micro- 

1  Certain  verbal  changes  have  been  made  in  reprinting  the  Introduction,  a 
few  sentences  have  been  omitted,  and  there  are  certain  additions,  which  are 
enclosed  in  brackets. 


338  ZOOLOGY 

scopes  will,  nevertheless,  be  able  to  select  from  nineteen  exercises, 
while  those  which  in  addition  are  unable  to  make  use  of  living- 
marine  animals  will  still  have  a  choice  from  seventeen  exercises.  A 
thorough  study  of  a  few  types,  rather  than  a  more  superficial  study 
of  many,  should  be  aimed  at. 

General  aim.  —  It  is  the  general  aim  of  these  exercises  to  interest 
as  well  as  to  train  the  pupil ;  indeed,  it  is  believed  that  the  awakening 
of  interest  is  the  best  preliminary  and  accompaniment  to  a  useful 
mental  training.  Since  young  persons  are  especially  interested  in 
living  animals,  observations  and  non-injurious  experiments  upon  the 
normal  reactions  and  the  methods  of  locomotion  of  animals  are 
required  in  nearly  every  exercise.  While  the  study  of  active  animals 
will  entail  much  additional  labor  on  the  part  of  the  teacher,  and 
some  additional  expense,  it  is  believed  that  the  results  will  justify 
the  cost.  In  order  to  carry  out  the  aim  of  these  exercises,  it  is  desir- 
able that  the  student  find  answers  to  his  questions,  as  far  as  practi- 
cable, from  the  object  before  him,  rather  than  from  the  teacher  or 
from  books.  Questions  involving  comparisons  between  the  types  have 
been  omitted,  not  because  they  are  regarded  as  unimportant,  but 
because  they  would  necessarily  vary  according  to  the  particular 
types  selected  and  the  order  in  which  these  types  are  studied.  How- 
ever, the  necessity  which  compels  their  omission  is  the  less  to  be 
regretted,  since  it  leaves  the  teacher  free  to  exercise  his  own  judg- 
ment and  experience  in  this  matter,  but  he  should  not  fail  to  supply 
such  questions. 

Sequence  of  exercises.  —  The  sequence  of  exercises  must  depend 
largely  upon  availability  of  material ;  but  it  is  desirable  that  closely 
related  types  should  be  studied  in  immediate  succession  to  facilitate 
comparisons.  The  following  are  suggested  for  courses  occupying 
different  periods  in  the  year  :  — 


LABOEATOEY   WORK 


339 


Whole  Year. 

First  Half. 

Second  Half. 

I.  Grasshopper 

I.  Grasshopper 

VII.  Crayfish 

II.  Butterfly 

II.  Butterfly 

VIII.  Daphnia 

III.  Beetle 

III.  Beetle 

XIV.  Hydra 

IV.  Fly 

IV.  Fly 

XV.  Paramecium 

XIII.  Starfish 

XIII.  Starfish 

XL  Slug 

X.  Nereis 

X.  Nereis 

XII.  Anodonta  or 

IX.  Earthworm 

IX.  Earthworm 

Unio 

VI.  Spider 

VI.  Spider 

IX.  Earthworm 

V.  Lithobius 

V.  Lithobius 

X.  Nereis 

VII.  Crayfish 

XVII.  Newt 

VI.  Spider 

VIII.  Daphnia 

XVIII.  Lizard 

V.  Lithobius 

XI.  Slug 

XVI.  Smelt 

IV.  Fly 

XII.  Anodonta  or  Unio 

XIX.  Sparrow 

III.  Beetle 

XIV.  Hydra 

XX.  Mouse 

XVII.  Newt 

XV.  Paramecium 

XL  Slug 

XXI.  Frog's  Egg 

XXI.  Frog's  Egg 

XII.  Anodonta  or 

XVI.  Smelt 

XVI.  Smelt 

Unio 

XVIII.  Lizard 

XVII.  Newt 

VII.  Crayfish 

XIX.  Sparrow 

XVIII.  Lizard 

VIII.  Daphnia 

XX.  Mouse 

XIX.  Sparrow 

XIV.  Hydra 

XIII.  Starfish 

XX.  Mouse 

XV.  Paramecium 

II.  Butterfly 

Equipment.  —  A  well-lighted  laboratory  provided  with  tables  is 
almost  necessary,  but  the  teacher  may  find  it  possible,  with  much 
additional  work  and  less  satisfactory  results,  to  conduct  the  exercises 
at  the  students'  ordinary  desks.  The  apparatus  required  will  depend 
upon  the  exercises  selected.  In  any  case  there  will  be  needed  at 
least  one  large  aquarium.  For  this  purpose  battery  jars  twelve  inches 
in  diameter  will  be  found  serviceable.  For  keeping  living  insects, 
cages  made  of  wire  netting,  placed  over  food  plants  growing  in  broad 
"  seed-pans,"  are  recommended.  An  ingenious  teacher  will  be  able 
to  make  many  cheap  substitutions  for  some  of  the  apparatus 
specified.  Thus  in  place  of  "  Stender  dishes "  tumblers  may  be 
used. 

Laboratory   books.  —  The    drawings    should    be    made    on   a  good 


340  ZOOLOGY 

quality  of  drawing  paper.  Tablets  made  of  unglazed  drawing  paper, 
about  eight  inches  by  ten  inches,  are  recommended.1  Where  loose 
sheets  are  employed  they  must  be  bound  at  the  end  of  the  course. 
The  drawings  should  be  made  with  pencil  of  a  hardness  (HHI1  or 
HHHH)  appropriate  to  the  paper,  and  kept  well  sharpened.  The 
use  of  colored  crayons  or  water  colors  is  to  be  discouraged.  Few 
pupils  can  employ  shading  to  advantage.  Students  are  to  be  in- 
structed that  pencil  lines  should  represent  boundaries  of  structures. 
The  names  of  the  parts  represented  must  be  designated  and  should 
be  the  simplest  applicable. 

Records  of  experiments,  answers  to  "Questions  on  External 
Anatomy,"  comparisons  drawn,  and  other  written  exercises  should 
be  brief.  They  should  not  be  made  upon  the  same  sheets  with  the 
drawings,  but  either  in  a  separate  note-book  or  on  sheets  of  the  same 
size  as  the  drawing  sheets  and  eventually  bound  up  with  them.2 

Observations  on  the  living  animal.  —  The  experiments  upon  living 
animals,  especially  such  as  involve  reactions  to  stimuli,  should  be 
repeated  two  or  three  times,  since  the  first  response  of  the  animal 
may  be  abnormal  or  irregular. 

Topics  for  further  study.  —  Under  this  heading  there  are  given  in 
each  exercise  suggestions  for  oral  instruction  by  the  teacher,  or  for 
reading  and  recitation  on  the  part  of  the  pupil,  in  connection  with 
the  laboratory  work  on  the  type.  The  teacher  will  find  aid  from  the 
larger  text-books,  encyclopedias,  systematic  works,  and  compendia  of 
Natural  History.  [The  accompanying  text-book  is  fitted  especially  to 
these  Topics.] 

Excursions.  —  The  teacher  is  urged  to  undertake,  so  far  as  prac- 
ticable, excursions  with  his  pupils  to  localities  where  the  organisms 
studied  in  the  laboratory  and  their  allies  can  be  seen  in  their  natural 
environment.  The  student  should  be  encouraged  to  collect  and  study 
insects,  mollusks,  and  other  invertebrates,  and  to  make  observations 
on  their  habits.  Directions  for  collecting  various  kinds  of  animals 


1  [Boyer's  Science  Tablets,  made  by  the  Central  School  Supply  Company, 
Chicago,  are  convenient.] 

2  The  Harvard  requirement  says:   The  laboratory  work  should  be  done 
under  the  immediate  supervision  of  the  teacher,  so  that  he  can  certify  that  the 
drawings  and  written  work  are  the  pupil's  own. 


LABORATORY   WORK  341 

are  given  in  the  Bulletin  of  the  U.  S.  National  Museum,  No.  39. 
Parts  A  to  M,  1891-1899  are  already  published. 

Material;  —  The  teacher  should  know  before  beginning  the  course 
which  of  the  types  he  can  obtain  alive  in  his  locality,  and  where  and 
in  what  months  they  can  most  readily  be  found.  He  should  know 
these  things  not  only  about  the  ten  types  selected  but  also  about 
others,  as  certain  types  may  prove  to  be  unobtainable  when  wanted. 
He  must  give  due  attention  to  the  difficulty  of  procuring  living 
material  during  cold  weather.  Pupils  should  be  encouraged,  where 
practicable,  to  aid  in  procuring  material  for  class  work ;  the  excur- 
sions recommended  may  be  utilized  to  some  extent  for  this  purpose. 

Correspondence  from  teachers  who,  as  a  result  of  their  experiences 
in  using  this  outline,  have  any  suggestions  to  offer  which  may  be 
incorporated  in  a  future  revision  of  it,  is  solicited. 

{Dealers  in  animals  for  class  work. —  Mr.  George  K.  Cherrie, 
Brooklyn  Institute  Museum,  Eastern  Parkway  and  Washington 
Avenue,  Brooklyn,  N.  Y.,  will  undertake,  after  September  1,  1900,  to 
supply  schools  with  the  animal  material  illustrative  of  most  of  the 
families  referred  to  in  the  text,  and  will  supply  schools  and  colleges 
with  preserved  animals  in  quantity  for  class  use. 

Dealers  in  live  animals  are  :  — 

Mr.  C.  J.  Maynard,  447  Crafts  Street,  West  Newton,  Mass. 

Mr.  F.  G.  Hillman,  New  Bedford,  Mass. 

Aquarium  Supply  Co.,  Delair,  N.  J. 

Messrs.  C.  E.  Blake,  1486  E.  69th  Street,  Chicago,  111.  (can  furnish 
some  of  the  material  alive). 

In  addition  to  the  foregoing,  preserved  material  will  be  supplied  by :  — 

The  Marine  Biological  Laboratory,  Woods  Holl,  Mass. 

Messrs.  II.  H.  &  C.  S.  Brimley,  Raleigh,  N.  C.  (also  some  living 
material). 

Mr.  F.  W.  Wamsley,  Acad.  Nat.  Sci.,  Philadelphia. 

Most  of  these  dealers  will  furnish  catalogues  of  material  on 
application.]  * 


342  ZOOLOGY 

EXERCISES 
I.     GRASSHOPPER    (Caloptenus  femur-rubrum) 

Caloptenus  (which  may  be  replaced  by  any  other  member  of  the 
Acrididse  or  by  a  cricket)  can  be  obtained  abundantly  in  the  autumn. 

DRAWINGS 

1.  Entire  animal,  left  side,  wings  in  place,      x  2. 

2.  Front  view  of  head,      x  4. 

3.  Posterior  view  of  antenna  and  first  and  third  legs  of  right  side 
drawn,  for  comparison,  one  below  the  other,      x  3. 

4.  Upper  surface  of  right  wings.     Draw  a  vertical  line  representing 
the  axis  of  the  body,  mark  the  anterior  (^1)  and  posterior  (P)  ends  of 
the  line,  and  draw  the  wings  one  behind  the  other  to  the  right  of  this 
line,      x  3. 

5.  Lateral  view  of  trunk  (left  side),  with  legs  and  wings  removed, 
x  3. 

6.  Mouth-parts,  arrange  in  a  column  as  in  No.  4.      x  5. 

7.  Compound  eye  (hand  lens),      x  10. 

QUESTIONS  ON  EXTERNAL  ANATOMY 

1.  Is  the  number  of  trunk  segments  constant?    (Count  segments  of 
three  or  more  individuals.) 

2.  Is  the  number  of  segments  in  the  leg  constant  in  the  correspond- 
ing legs  of  three  individuals;  in  all  the  legs  of  the  same  individual? 

3.  Describe  in  not  over  one  hundred  words  the  difference  between 
the  oldest  and  the  youngest  individual  you  have,  in  respect  to  (a)  size 
of  trunk  ;  (&)  size  of  wings ;  and  (c)  other  characters. 

OBSERVATIONS  ON  THE  LIVING  ANIMAL 

1.  Note  the  respiratory  movements   of  the  abdomen.     Count  the 
number  per  minute.     Does  the  number  vary  with   the   individual? 
Does  it  vary  with  external  conditions  such  as  temperature  and  stimu- 
lation ? 

2.  Holding  the  grasshopper  in  the  right  hand,  with  the  left  put  the 
tip  of  a  blade  of  green  grass  to  the  mouth.     Note  the  movements. 


LABORATORY   WORK,  II  343 

How  does  the  grasshopper  react  to  different  substances  on  the  end  of 
the  grass  blade  ? 

3.  Place  the  grasshopper  under  a  bell-glass  and  note  and  record  the 
position  of  the  legs  in  successive  phases  of  walking. 

TOPICS    FOR    FURTHER    STUDY 

1.  Habitat  and  food  of  the  grasshopper.  2.  Distribution  of  the 
species  studied.  3.  Development  (general  and  external).  4.  Allies 
of  the  grasshopper :  cricket,  green  locusts,  walkingsticks,  Mantis, 
cockroaches,  earwigs,  dragon-flies,  ephemerids,  termites,  the  Neurop- 
tera,  Hemiptera,  and  Homoptera. 

II.     BUTTERFLY 

Any  one  of  various  species  whose  larvae  can  be  obtained  alive  near 
the  end  of  September  may  be  employed.  The  cabbage  butterfly 
(Pieris),  the  milkweed  butterfly  (Danais),or  the  swallow-tail  butterfly 
(Papilio)  will  meet  these  conditions. 

DRAWINGS 

1.  Imago  :  Dorsal  view,  wings  expanded,      x  1  or  2. 

2.  Imago :  Left  side,  wings  closed.     (The  bodies  in  1  and  2  are  to 
be  drawn  parallel  to  each  other.)      x  1  or  2. 

3.  Imago  :  Front  of  head,      x  10. 

4.  Pupa :  Left  side. 

5.  Full-grown  larva  :  Dorsal  view. 

6.  Full-grown  larva  :  Left  side. 

QUESTIONS  ON  EXTERNAL  ANATOMY 

1.  How  many  segments  behind  the  head  in  (a)  the  imago?  (6)  the 
larva?  (c)  the  pupa? 

2.  What  external  organs   of  the   imago  can  be  identified  in  the 
pupa? 

3.  Whiicti  feet  of  the  larva  correspond  to  those  of  the  imago? 

OBSERVATIONS  ON  THE  LIVING  LARVA 

Each  student  (or  group  of  students)  should  be  provided  with  a 
glass  vessel  covered  with  netting  and  containing  food  leaves  for  keep- 
ing the  larva  during  pupation. 


344  ZOOLOGY 

1.  How  is  locomotion  effected  ?     Illustrate  by  diagrams. 

2.  How  does  the  larva  feed?     Observe  and  record  the  movements 
of  the  mouth-parts  and  of  the  head  during  feeding.     Draw  the  outline 
of  a  partly  eaten  leaf. 

3.  (This  observation  must  extend  through  several  days.)      Make  and 
record  observations  upon  the  act  of  pupation. 

TOPICS    FOR    FURTHER    STUDY 

1.  The  habits  and  food  of  butterflies.  2.  The  number  of  broods  of 
butterflies  during  a  single  season  and  seasonal  dimorphism.  3.  Pro- 
tective resemblance  and  mimicry.  4.  The  larger  divisions  and  com- 
moner native  forms  of  Lepidoptera.  (Examples  of  Lepidoptera 
illustrating  the  commoner  native  types  should  be  shown  and  students 
encouraged  to  collect  and  classify  them.)  5.  The  Hymenoptera : 
their  structure,  classification,  and  habits. 

III.     BEETLE 

The  May-beetle  and  the  potato-beetle  are  recommended  for  studies 
from  alcoholic  specimens.  If  these  are  not  available  for  the  "  Obser- 
vations on  the  Living  Animal,"  any  other  slow-creeping  species 
may  be  employed. 

DRAWINGS 
(From  alcoholic  specimens) 

1.  Dorsal  view,  naming  parts,      x  8. 

2.  Remove  the  antenna,  mandible,  maxillae,  and  legs  of  right  side. 
Draw  posterior  view  of  each  part.     Use  lens,      x  15. 

3.  Remove  the  wing  case  and  membranous  wing  from   left  side. 
Draw  wing  (a)  folded,   (b)  unfolded,  indicating  position  of  creases. 
Draw  imaginary  cross-section  of  the  folded  wing. 

4.  Draw  beetle-  from   left   side,   indicating    position    of   removed 
wings,      x  8. 

5.  (Optional.)     Draw  larva  from  left  side,      x  8. 

QUESTIONS  ON  EXTERNAL  ANATOMY 

1.  How  many  segments  has  the  beetle  behind  the  head? 

2.  (Optional.)     How  many  segments  has  the  larva? 


LABOEATORY    WORK,   IV  345 

3.  From  which  segments  do  the  wings  arise  ?     The  legs  ? 

4.  Of  how  many  segments  is  each  foot  composed  ? 

OBSERVATIONS  ON  THE  LIVING  ANIMAL 

1.  Place  a  beetle  upon  a  piece  of  white  paper ;  observe  the  order  of 
movement   of  the   legs  in  locomotion,  and  record  by  some  graphic 
method.1     Analyze   the    movement  of  a  leg  of  each  pair;  how  does 
it  help  the  animal  to  move  ?     Compare  with  grasshopper. 

2.  Placing  a  bit  of  potato  leaf  (or  other  green  leaf)  at  the  mouth  of 
the  beetle,  notice  the  movements  of  the  mouth-parts  in  feeding. 

3.  Observe  and  record  the  movements  of  the  feet  of  the  larva  in 
locomotion. 

TOPICS    FOR    FURTHER    STUDY 

1.  Stages  in  the  development  of  a  beetle.  2.  The  principal  classes  of 
beetles :  illustrate,  e.g.,  runners,  divers,  short-wings  or  rove-beetles, 
carrion-beetles,  wool-beetles,  stag-beetles,  tumble-bugs,  May-beetles, 
boring  beetles,  snappers,  fireflies,  bark-beetles,  weevils,  buck-bee- 
tles, leaf  eaters,  ladybirds.  (Examples  of  these  should  be  shown  and 
students  encouraged  to  collect  and  classify  them.)  3.  The  food  of 
beetles.  4.  Economic  importance:  («)  injurious  beetles  —  destructive 
to  vegetation,  to  wood,  to  grain,  to  meat,  to  fur  and  cloth,  to  useful 
animals;  (6)  useful  beetles  —  advantageous  by  acting  as  scavengers, 
by  killing  injurious  insects. 


IV.     HOUSE-FLY    OR    BLUEBOTTLE    FLY    (Musca    domestica 
and  M.  vomitorid) 

To,  get  larvae  of  the  bluebottle  fly  it  is  only  necessary  to  expose 
flesh,  even  on  a  warm  winter  day,  a  week  or  so  before  the  larvae  are 
needed  for  class  work.  The  larvae  may  be  fed  upon  bran,  and  when 
well  grown  may  be  prevented  from  pupating  by  being  kept  at  a  tem- 
perature sligh'tly  above  the  freezing-point. 

1  An  excellent  method,  proposed  by  Professor  F.  E.  Lloyd  of  Teachers' 
College,  New  York,  is  to  have  the  beetle  walk  from  an  anilin  ink  pad  (ordi- 
nary stamping  pad)  to  the  paper.  The  ink  on  the  feet  will  leave  a  print  of 
the  steps  on  the  paper. 


346  ZOOLOGY 


DRAWINGS 

1.  Imago,  dorsal  view,  wings  in  place,      x  10. 

2.  Left  side,  showing  stigmata ;  wings  having  been  removed  and 
preserved  for  further  study,      x  10. 

3.  Front  view  of  head,  with  antennae  (lens),      x  15. 

4.  Posterior  view  of  first  pair  of  legs,      x  15. 

5.  Dorsal  view  of  wing  and  balancer  of  the  right  side,      x  15. 

6.  Abdomen,  ventral  aspect,      x  10. 

7.  (Optional.}     Egg  of  fly.      x  10. 

8.  (Optional.}     Larva,  side  view,      x  7. 


QUESTIONS  ON  EXTERNAL  ANATOMY 

1.  How  many  body-segments  has  the  fly  behind  the  head? 

2.  How  many  segments  in  the  antenna? 

3.  How  many  segments  in  the  leg  ?     (Compare  with  grasshopper.) 

4.  Can  you  detect  any  difference  between  different  individuals  of 
the  same  species  in  respect  to  form  of  the  head  and  eyes  ? 


OBSERVATIONS  ON  THE  LIVING  ANIMAL 

Each  student  should  be  provided  with  the  following:  (1)  a  bell- 
jar  (or  any  broad  glass  vessel)  containing  a  fly  and  covered  with  a 
card ;  (2)  a  soup-plate  ;  (3)  vials  of  various  colored,  pungent,  sweet, 
and  neutral  substances,  such  as  white  sugar,  vinegar,  butter  (prefer- 
ably rancid),  ground  gypsum,  white  sugar  reddened  with  carmine,  |% 
acetic  acid,  molasses. 

1.  Place  on  the  soup-plate  at  a  little  distance  apart  some  sugar, 
a  drop  of  vinegar,  grains  of  sugar,  and  a  drop  of  water.     Invert  the 
bell-jar  containing  a  fly,  over  the  soup-plate,  and  carefully  move  the 
bell-jar  until  it  covers  all  of  the  substances.     Note  all  the  movements 
of  the  fly  for  five  minutes  — these  are  the  instinctive  movements  of  the 
fly  in  the  given  situation;  note  especially  its  movements  with  refer- 
ence to  the  substances. 

2.  Try  the  same  fly  with  other  combinations  such  as  vinegar,  mo- 
lasses, water. 

3.  Try  a  second  fly  with  one  of  the  same  combinations  of  substances. 


LABORATORY   WORK,    V  347 

QUESTIONS 

By  what  substances  are  the  flies  most  attracted  ?  What  is  the  par- 
ticular quality  which  seems  to  attract?  What  sense  (sight,  smell,  or 
other)  seems  to  have  most  influence? 

TOPICS    FOR    FURTHER    STUDY 

1.  The  habitat  and  food  of  the  fly.  2.  Development.  3.  Respira- 
tion. 4.  The  parasites  of  the  fly.  5.  Other  Diptera:  Glossina 
(tsetse-fly),  bot-flies,  Syrphus,  horse-fly,  black-fly,  crane-flies,  gall 
gnats,  gnats,  mosquitoes,  sheep-ticks  or  lice-flies,  fleas,  and  jiggers. 
6.  The  economic  importance  of  Diptera  as  parasites  on  animals  and 
plants,  as  gall  producers,  as  destroyers  of  grain,  as  distributers  of 
disease,  and  as  scavengers. 

V.      LITHOBIUS 

This  myriapod  may  be  obtained  under  woodpiles,  or  damp  leaves 
in  woods,  even  in  late  autumn  or  during  mild  days  in  winter. 

DRAWINGS 

1.  Dorsal  view,     x  5. 

2.  Head,  under  side,  naming  principal  parts,  e.g.  antennae,  jaws, 
first  trunk  appendages,  etc.      x  15. 

3.  Head,  upper  side,      x  15. 

4.  Two  consecutive  segments  seen  from  left  side,  showing  legs  and 
stigma,     x  10. 

QUESTIONS  ON  EXTERNAL  ANATOMY 

1.  How  many  segments  in  the  body?     Is  the  number  constant? 
(Examine  two  or  three   individuals.)      Are   new   segments  formed 
throughout  life  ?     Compare  with  earthworm. 

2.  How  many  segments  in  the  antenna?     Is  this  number  constant? 

3.  How  many  segments  in  the  leg? 

OBSERVATIONS  ON  THE  LIVING  ANIMAL 

Each  student  should  be  provided  with  the  following:  (1)  a  glass 
rod  as  in  No.  VI.  or  toothpicks;  (2)  vial  of  cologne;  (3)  vial  of  2% 
acetic  acid;  (4)  a  soup-plate;  (5)  a  pane  of  glass  large  enough  to 
cover  the  plate ;  (6)  forceps  to  hold  Lithobius. 


348  ZOOLOGY 

1.  Study  the  movement  of  a  single  leg  and  draw  three  of  its  phases. 
The  Lithobius  is  held  in  the  covered  plate.1 

2.  Make  a  diagram  exhibiting  the  coordination  of  leg  movement. 

3.  Touch  the  antenna  with  a  needle.     Response  ? 

4.  Bring  a  clean  glass  rod  near  to  an  antenna  ;  then  the  rod  dipped 
in  cologne  ;  then  cleaned  and  dipped  in  acetic  acid.     Record  results 
and  conclusions. 

5.  Does  Lithobius  tend  to  move    from  or   toward   the  source   of 
light? 

6.  Place  on  a  piece  of  filter  paper,  one-half  wet  and  one-half  dry, 
and  note  reaction  at  edge  of  wet  part. 

TOPICS    FOR    FURTHER    STUDY 

1.  Habitat  and  food  of  chilopods  in  general.  2.  Distribution  of 
Lithobius.  3.  Allies  of  Lithobius  :  Scutigera,  Scolopendra,  Geophilus, 
Polydesmus,  Julus  ;  their  habitats. 

VI.      SPIDER  (Argiope  and  Theridium) 

The  large  black  and  yellow  garden  spider  (Argiope)  should  be 
obtained  in  the  fall  and  preserved  in  alcohol.  The  house  cobweb 
spider  (Theridium)  can  be  obtained  alive  throughout  the  year  in  un- 
swept  corners,  especially  in  cellars.  Despite  its  small  size  it  will 
serve  for  the  studies  on  activities.  It  may  be  kept  in  a  4-inch  battery 
jar  where  it  will  spin  its  web.  Feed  upon  flies,  plant-lice,  and  other 
insects.  Other  spiders  may  be  substituted  for  these. 

DRAWINGS   (of  Argiope) 

1.  Ventral  view  showing  appendages,  opening  to  air  sacs,  and  spin- 
ning glands,     x  5. 

2.  Side  view  (left),      x  5. 

3.  Front  dorsal  view  of  head,  showing  eyes  and  jaws  (hand  lens). 
x  10. 

OBSERVATIONS  ON  THE  LIVING  ANIMAL 

Each  student  should  be  provided  with  the  following  :  (1)  a  glass 
rod  about  10  crn.  long  and  2  mm.  in  diameter,  or  toothpicks  ;  (2)  a 


movements  of  the  animal  may  be  reduced  by  adding  a  little  ether,  or 
by  holding  the  body  with  a  forceps. 


LABORATORY   WORK,    VII  349 

vial  of  essence  of  heliotrope ;  (3)  a  vial  of  cologne ;  (4)  a  vial  of  di- 
lute ammonia ;  (5)  a  glass-covered  box  about  8  inches  cube. 

1.  Offer  to  the  spider  the  end  of  the  glass  rod,  first  clean,  then  dipped 
in  essence  of  heliotrope  ;  cleaned  and  dipped  in  cologne ;  in  ammonia. 
Note  and  record  movements. 

2.  Place  the  spider  in  the  box  and  note  for  ten  minutes  its  instinc- 
tive movements. 

3.  Leave  the  spider  in  the  box  for  a  day  or  two  and  draw  the  web ; 
in  successive  stages  of  formation  if  possible. 

TOPICS    FOR    FURTHER    STUDY 

1.  Habitat  and  food  of  Argiope  and  Theridium.  2.  Distribution 
of  these  spiders.  3.  Spinning  habits  of  spiders  in  general :  forms  of 
webs  and  nests  of  the  different  classes  of  spiders  ;  economic  impor- 
tance of  spiders'  webs.  4.  Biting  and  poisonous  spiders. 

VII.     CRAYFISH  (Cambarus) 

Crayfish  can  be  obtained  from  small  streams  in  most  parts  of  the 
United  States,  except  New  England.  They  are  also  for  sale  in  the 
markets  of  large  cities,  and  are  easily  transported  and  kept  alive 
for  days  in  damp  moss.  They  may  eventually  be  transferred  to  an 
aquarium  containing  water  not  more  than  an  inch  deep.  Feed  upon 
earthworms  or  pieces  of  meat.  The  crayfish  may  be  replaced  by 
the  lobster. 

DRAWINGS 

1.  View  from  left  side,  taking  care  to  preserve  accurately  the  pro- 
portions.     X  1.5. 

2.  Ventral  view.     (Omitting  legs.)      x  1.5. 

3.  Draw  the  posterior  aspect  of  the  following  appendages  of  the 
right  side  of  animal,  without  removal  from  body,      x  2. 

(a)  small  antenna.  (<7)  4th  thoracic  appendage. 

(&)  large  antenna.  (A)  5th  thoracic  appendage. 

(c)  mandible.  (i)  8th  (last)  thoracic  appendage. 

(d)  1st  maxilla.  (fc)  4th      abdominal      appendage 
(<?)  2d  maxilliped.  (swimmeret). 

(/)  3d  maxilliped.  (/)  last  abdominal  appendage. 


350  ZOOLOGY 

4.  Draw  right  side  of  thorax   (carapace  previously  removed)  to 
show  the  number  and  position  of  gills,     x  2. 

5.  Draw  dorsal  aspect  of  eye-stalk,     x  4. 

QUESTIONS  ON  EXTERNAL  ANATOMY 

1.  How  many  segments  in  the  last  thoracic  appendage?    Number 
the  segments  upon  your  drawing,  beginning  at  the  proximal  (attached) 
end.     Number  as  far  as  you  can  the  homologous  segments  upon  the 
other  thoracic  appendages  drawn. 

2.  How  can  you  homologize l  with  one  another  the  swimmerets,  the 
legs,  and  the  mouth  parts  ?     Give  evidence  for  each  step  and  indicate 
results  on  the  drawings  already  made. 

3.  Which  is  the  least  differentiated  of  the  series  of  appendages?2 

4.  What  is  the  gill  formula  of  the  animal  in  hand? 

OBSERVATIONS  ON  THE  LIVING  ANIMAL 

Each  student  should  be  provided  with  the  following:  (1)  soup- 
plate;  (2)  needle;  (3)  vial  of  dilute  ammonia;  (4)  vial  of  5%  acetic 
acid  ;  (5)  vial  of  carmine. 

1.  Hold  a  living  crayfish  in  a  soup-plate  of  water  so  that  the  free 
edge  of  its  carapace  is  near  the  surface.    Put  a  few  drops  of  the  carmine 
into  the  water  in  front  of  the  thorax ;  behind  the  thorax ;  between 
the  legs.     Draw  a  diagram  showing  the  currents.     What  is  the  use  of 
these  currents,  and  by  what  mechanism  are  they  produced? 

2.  Hold  the  living  crayfish  so  that  its  head  and  anterior  half  only 
of  thorax  are  submerged ;  observe  what  takes  place  at  hinder  edge  of 
carapace.     Hold  the  crayfish  so  that  abdomen  and  posterior  half  only 
of  carapace  are  submerged  ;  what  takes  place  at  anterior  edge  of  cara- 
pace ?    Interpretation  ? 

3.  Determine  the  function  of  each  pair  of  legs  used  in  locomotion 
and  the  correlation  in  their  movements. 

1  The  idea  of  homology  should  be  made  clear.    The  pupil  should  indicate  the 
protopodite  (p),  exopodite  (ex),  and  endopodite  (en)  upon  all  the  drawings  of 
appendages. 

2  The  teacher  should  make  use  of  the  crayfish  to  explain  the  principle  that 
different  organs  have  a  different  degree  of  specialization  or  "  differentiation." 
This  will  lead  to  the  topic  of  Division  of  Labor,  as  indicated  below. 


LABORATORY   WORK,    VIII  351 

4.  To  the  tip  of  one  of  the  large  antennae  and  to  the  small  antennae 
apply  (a)  the  point  of  a  needle;   (/;)  the  vapor  of  ammonia;   (c)  a 
drop  of  water;  (d)  a  drop  of  5%  acetic  acid.   Tests  («)  and  (ft)  should 
be  performed  upon  the  antenna  of  one  side  and  (rt),  (c),  and  (d)  upon 
that  of  the  other.     Record  the  results.   What  inferences  do  you  draw  ? 

5.  Wave  the  hand  over  the  crayfish.     Does  it  react  ?     If  possible 
flash  a  light  at  its  head.     Can  the  crayfish  see?      Cover  the  eye-stalks 
with  wax.     Does  it  still  react  to  a  movement  of  the  hand? 

TOPICS    FOR    FURTHER    STUDY 

1.  The  habitat  and  food  of  the  crayfish.  2.  The  geographical  dis- 
tribution of  crayfishes.  3.  Other  stalk-eyed  Crustacea  (long  and  short 
tailed)  ;  lobsters,  shrimps,  hermit-crabs,  spider-crabs,  edible  crabs. 
4.  Economic  importance  of  stalk-eyed  Crustacea.  5.  The  breeding 
habits  and  general  development  of  crayfish  and  lobster.  6.  The 
capacity  for  regeneration  in  the  higher  Crustacea  and  the  occurrence 
of  monstrosities.  7.  Division  of  labor  in  the  appendages  of  the  cray- 
fish. 

VIII.    DAPHNIA 

Daphnia  may  be  obtained  from  pools  at  almost  any  time  of  the  year 
except  midwinter.  They  may  be  reared  in  large  numbers  in  aquaria 
properly  stocked  with  decaying  plants,  upon  which  they  feed.  Select 
for  class  work  the  largest  individuals  (females),  which  may  attain  a 
length  of  2  mm. 

DRAWING 

Place  a  living  animal  on  a  slide  under  a  cover-glass,  and  with  the 
aid  of  the  simple  microscope  draw  a  side  view,  x  20. 

OBSERVATIONS  ON  THE  LIVING  ANIMAL 

Each  student  should  be  provided  with  the  following :  (1)  Stender 
dish ;  (2)  pipette ;  (3)  watch-glass  containing  Daphnias ;  (4)  three 
pieces  of  glass  tubing  20  cm.  long  and  4  mm.  bore,  with  two  corks 
to  fit. 

1.  Place  a  Daphnia  in  the  straight  glass  tube  (6)  filled  with  clear 
water  and  corked  at  both  ends.  (Exclude  air-bubbles  in  corking.) 
Place  parallel  to  the  rays  from  the  source  of  light  (preferably  lamp 


352  ZOOLOGY 

light)  and  cut  off  side  lights.     Observe  and  record  movements  or  lack 
of  movements. 

2.  Place   a  Daphnia  in  a  tube  containing  a  single  wad  of  algse; 
place  another  Daphnia  in  a  tube  containing  a  small  pebble  ;  observe 
and  record  behavior  with  reference  to  the  foreign  body. 

3.  (Optional.}     Place  an  egg-bearing  female  in  a  Stender  dish  con- 
taining bits  of  decaying  plant.     After  seven  days  count  the  number  of 
individuals.     Compare  with  the  number  in  a  similar  dish  kept  (by 
the  teacher)  for  seven  days  in  a  cool  place  (5°  to  10°  C.). 

TOPICS    FOR    FURTHER    STUDY 

1.  The  habitat  and  food  of  Daphnia.  2.  Allies  of  Daphnia :  Bran- 
chipus,  Cyclops,  Cypridopsis,  barnacles,  trilobites.  3.  The  pupil  should 
learn  to  distinguish  Daphnia,  Cyclops,  and  the  other  Entomostraca  in 
the  aquarium  by  their  locomotion. 


IX.     EARTHWORM    (AllololopJiora  or  Lumbricus) 

Various  species  may  be  used.  During  the  winter  time,  when  the 
ground  is  frozen,  earthworms  are  best  sought  under  compost  heaps; 
or  they  may  be  kept  in  laboratory  in  flower-pots  containing  rich,  moist 
vegetable  mould  and  covered  by  a  glass  plate.  They  may  be  fed 
upon  fallen  leaves  placed  in  the  pots. 

DRAWINGS 

(From  alcoholic  specimens) 

1.  Whole  animal,  dorsal  view,      x  2. 

2.  Head  end,  6  or  8  segments,  ventral  view,      x  5. 

3.  Tail  end,  6  or  8  segments,  ventral  view,      x  5. 

4.  Two  adjacent  middle  segments,  showing  setae,      x  5. 

5.  Cross-section,  showing  position  of  setse.      x  5. 

QUESTIONS  ON  EXTERNAL  ANATOMY 

1.  Count  the   number   of  segments  of  two  or  three  individuals. 
Are  they  the  same?     Inference  to  be  drawn  from  the  result? 

2.  Where  does  growth  in  length  take  place?    Evidence  for  your 
conclusion  ? 


LABORATORY   WORK,  X  353 

OBSERVATIONS  ON  THE  LIVING  ANIMAL. 

Each  student  should  be  provided  with  the  following  :  (1)  plate  cov- 
ered with  moist  filter  paper;  (2)  hand  lens;  (3-5)  vials  containing 
sugar  solution,  acetic  acid,  and  beef  extract ;  (6)  four  new  toothpicks  ; 
(7)  pipette. 

1.  Touch  with  a  toothpick,  first  the  head  end,  then  the  tail  end  of 
the  worm ;  to  which  contact  does  it  react  more  strongly  ? 

2.  Place  the  earthworm  near  the  window.       Does  it  move  toward 
or  from  the  light  ? 

3.  With  the  breath  blow  upon  the  head  end  of  the  worm.     Record 
results.     Are   results  due  to  the   warmth   of   the   breath  or  to  the 
current  of  air?     To  test,  send  a  puff  upon  the  head  with  a  pipette. 

4.  Bring  near  to  the  head  end  in  succession  the  ends  of  toothpicks 
dipped  in  water,  in  sugar  solution,  in  acetic  acid,  and  in  beef  extract. 
How  does  the  worm  react  to  each  fluid  ? 

5.  Place  the  earthworm  on  a  piece  of  filter  paper  two-thirds  of  which 
is  wet.     Reaction  of  worm  at  edge  of  wet  part  ?     How  do  these  reac- 
tions of  the  earthworm  accord  with  its  ordinary  movements  out  of 
doors  ? 

6.  When  the.  head  end  is  being  thrust  out  forward,  in  what  phase 
(contraction  or  expansion)  is  the  middle  of  the   worm?     The   tail 
end?    In  what  direction  does  the  contraction  wave  pass? 

TOPICS    FOR    FURTHER    STUDY 

1.  Habitat  and  food  of  the  earthworm.  2.  Economic  importance 
of  earthworms.  3.  Allies  of  the  earthworm:  Nais,  Dero,  Tubifex, 
the  leeches,  the  Gephyrea,  the  Bryozoa. 

X.     NEREIS 

Nereis  can  be  obtained  at  the  sea-shore  by  digging  in  mud  flats 
between  tide  lines.  It  can  be  transported  in  damp  sand  or  seaweed, 
and  will  remain  alive  for  several  days  in  a  shallow  vessel  filled  with 
sea-water  and  kept  in  a  cool  place. 

DRAWINGS 

{From  alcoholic  specimens) 
1.  Whole  animal,  dorsal  view.     Natural  size. 
2  A 


354  ZOOLOGY 

2.  Head  end,  dorsal  view,      x  5. 

3.  Tail  end,  dorsal  view,      x  5. 

4.  Two  adjacent  middle  segments,  dorsal  view,      x  5. 

5.  Posterior  aspect  of  a  single  middle  segment,  showing  parapodia. 
x  8. 

QUESTIONS  ON  EXTERNAL  ANATOMY 

1.  Which  segments  are  most  specialized? 

2.  Does  the  number  of  segments  increase  during  life?     Compare 
several  worms. 

3.  Which  segments  are  last  formed  in  the  individual's  development  ? 

OBSERVATIONS  ON  THE  LIVING  ANIMAL 

(Two  persons  may  work  together  upon  a  single  Nereis.}  Each  stu- 
dent should  be  provided  with  the  following:  (1)  hand  lens;  (2) 
needle  ;  (3,  4)  vials  containing  5%  sugar  solution  and  5%  acetic  acid  ; 
(5)  pipette. 

1.  How  is  locomotion  accomplished  by  Nereis?     Analyze  the  move- 
ments  involved    in    locomotion.      Relation    of   phases   of   writhe    to 
phases  of  stroke  and  recovery  of  fin.     Form  of  fin  at  various  phases 
of  its  movement.      Indicate  by  diagrams  the  relations  which   you 
discover. 

2.  Touch  the  head  with  a  needle;    what  movements?     The  tail; 
what   movements?      What   faculty   in   Nereis   is   indicated   by   the 
changes  of  movement  after  contact  ? 

3.  Drop  quietly,  by  means  of  a  pipette,  sea-water  upon  the  head  end 
and  the  middle  of  Nereis;  repeat  with  acetic  acid;  with  sugar  solu- 
tion.    What  difference  in  the  movements?     What  faculty  in  Nereis  is 
indicated  by  these  differences  in  movement? 

TOPICS    FOR    FURTHER    STUDY 

1.  Habitat  and  food  of  Nereis.  2.  Its  distribution.  3.  Its  allies  : 
Autolytus,  Lepidonotus,  Amphitrite,  Serpula,  etc.  4.  The  round 
worms  and  flat  worms. 

XL     SLUG    (Limax) 

Slugs  may  be  found  during  the  winter  in  greenhouses  and  during 
the  spring  and  autumn  in  gardens  and  orchards,  under  boards  and 
stones.  They  may  be  kept  for  considerable  periods  in  a  box  whose 


LABORATORY   WORK,   XI  355 

bottom  is  covered  with  damp  moss ;  they  may  be  fed  upon  fresh 
apples,  cabbage  leaves,  etc.  Limax  maximus  is  to  be  preferred  on 
account  of  its  large  size. 

DRAWINGS 
(From  the  living  individual) 

1.  Dorsal  view,  showing  mantle,  foot,  respiratory  opening,  head  and 
tentacles,      x  1.5  to  3. 

2.  View  of  right  side,      x  1.5  to  3. 

3.  Front  view,  showing  tentacles,  mouth,  and  lips  of  slime-gland, 
x  3. 

OBSERVATIONS  ON  THE  LIVING  ANIMAL 

Each  student  should  be  provided  with  a  pane  of  glass,  8  by  10 
inches. 

1.  Place  the  slug  on  the  glass  and  study  its  locomotion  from  the 
under  side  of  the  plate.     Describe  in  the  note-book  what  is  seen. 

2.  Place  the  slug  on  the  glass  plate,  hold  the  plate   vertical   and 
parallel  to  the    window,  the  slug  being  horizontal  and  parallel    to 
one  edge  of  the  pane  ;  shield  from  lateral  lights.     Having  made  in  the 
note-book  an  outline  to  represent  the  plate,  indicate  in  this  the  posi- 
tion of  the  slug  at  the  beginning  of  the  experiment  and  at  intervals  of 
ten  seconds  for  about  a  minute.     Repeat.     A  piece  of  planed  board  is 
better  than  the  glass  plate,  excepting  that  it  cannot  be  kept  so  clean. 

3.  Place  the  plate  horizontal  near  a  window  and  let  the  slug  be  par- 
allel to  the  window.      Do  not  let  direct  sunlight  fall  upon  it.     Plot  in 
the  note-book,  as  before,  the  position  of  the  axis  of  the  slug  at  inter- 
vals of  ten  seconds.     Repeat. 

4.  Note  the  reaction  of  the  slug  to  contact  on  different  parts  of  the 
body  :  tail,  head,  antennae,  edge  of  mantle. 

5.  Does  the  slug  react  to  passes  of  the  hand  ?     To  moisture  ? 

,      TOPICS    FOR    FURTHER    STUDY 

1.  The  habitat,  food,  and  methods  of  feeding  of  the  slug.  2.  Its 
distribution.  3.  The  economic  importance  of  slugs.  4.  The  shell  of 
the  slug.  5.  Allies  of  the  slug :  Helix,  Pupa,  Limnsea,  Physa,  Planor- 
bis,  Littorina,  Fulgur,  Fissurella,  JBoli's,  Chiton,  the  Nautilus,  and 
other  cephalopods  recent  and  fossil.  „ 


356  ZOOLOGY 


XII.     FRESH-WATER  CLAM  (Anodonta  or  Unio} 

Venus  may  be  substituted  for  these ;  and  Mya  is  a  favorable  object 
for  this  study.  Anodonta  or  Unio  may  be  obtained  from  most 
streams  and  ponds  at  any  time  of  the  year  except  midwinter.  This 
exercise  will  therefore  be  best  taken  in  the  spring  or  autumn.  To 
prepare  animals  for  the  study  of  the  soft  parts,  place  them  in  hot 
water  (60°  C.)  for  a  few  minutes ;  the  valves  will  then  open  so  that 
the  muscles  can  be  cut  where  they  join  the  shell. 

DRAWINGS 

1.  Exterior  of  left  valve,  showing  lines  of  growth,  beak,  and  margin. 
Natural  size. 

2.  Interior  of  right  valve ;  name  some  of  the  more  important  parts, 
such  as  margin,  scar  of  mantle,  scars  of  adductor  muscles,  and  retrac- 
tor of  foot,  hinge.     Natural  size. 

3.  Bit  of  fractured  edge  of  burnt  shell,  to  show  layers,      x  5. 

4.  Remove  the  left  valve  from  the  killed  animal  and  draw  the  exter- 
nal form  of  the  soft  parts  from  the  left  side,      x  2. 

5.  Laying  back  the  mantle,  draw  in  place  gills  (showing  surface 
structure),  body,  foot,  and   labial   palps;   mark   anterior,   posterior, 
dorsal,  and  ventral  surfaces  of  the  body,      x  2. 

6.  Draw  an  imaginary  cross-section  made  through  the  middle  of  the 
body. 

QUESTIONS  TO  BE  ANSWERED   BY  INFERENCE  FROM  STRUCTURE 

1.  How  does  the  shell  grow? 

2.  How  does  the  animal  close  its  shell ;  how  open  it? 

3.  How  does  the  animal  gain  its  food  ? 

OBSERVATIONS  ON  THE  LIVING  ANIMAL 

Every  student  should  be  provided  with  the  following  :  (1)  vial  con- 
taining finely  powdered  carmine  in  water ;  (2)  vial  of  carmine  in  5  % 
acetic  acid;  (3)  carmine  in  5%  sulphuric  acid  ;  (4)  carmine  in  sugar 
solution  ;  (5)  pipette  ;  (6)  4-inch  battery  jar  half  full  of  water. 

1.  Notice  in  a  living  individual  in  the  aquarium  the  movements  of 
the  mantle,  especially  at  the  posterior  end. 


LABORATORY   WORK,   XIII  357 

2.  Hold  the  clam  just  below  the  surface  of  the  water  and  by  means 
of  a  pipette  place  some  carmine  suspended  in  water  near  the  poste- 
rior end.     Notice  the  results.     How  are  they  to  be  interpreted  ? 

3.  Offer  carmine  in  sugar  solution;  in  acetic  acid;  in    sulphuric 
acid.     Is  there  any  difference  in  the  results  ? 

TOPICS    FOR    FURTHER    STUDY 

1.  Habitat  and  food  of  Anodonta  (or  Unio).  2.  Geographical  dis- 
tribution of  fresh-water  clams.  3.  General  development.  4.  Allied 
animals  from  fresh  water,  such  as  the  Unionidse  and  Cycladidse  ;  and 
from  the  sea,  such  as  the  Myidae,  Veneridse,  Arcidse,  Aviculidse,  Pecti- 
nidae,  and  Ostreidae. 

XIII.  STARFISH  (Asterias  vulgaris) 

Starfishes  can  be  readily  got  at  low  tide  in  rock  pools  and  on  piles 
and  walls  at  the  sea-shore.  They  may  be  transported  alive  consider- 
able distances,  if  packed  in  wet  eel-grass  or  seaweed.  The  living 
animals  may  be  placed  for  study  in  a  soup-plate  full  of  sea-water,  or 
water  containing  about  2.5  %  sea  salt.  Dry  preparations,  for  the  study 
of  the  hard  parts,  may  be  made  as  follows  :  Leave  a  living  starfish  in 
a  shallow  dish  of  warm,  fresh  water  until  fully  expanded.  Next  dip 
it  into  boiling  water  until  hardened,  and  then  dry  it  in  the  sun  or  in 
a  slow  oven. 

DRAWINGS 

(Nos.  1,  2,  4,  and  5  from  dried  specimen,  No.  3  from  an  alcoholic  one.) 

1.  Aboral  view.     Natural  size. 

2.  Oral  surface  of  arm  showing  ambulacral  groove.     Natural  size. 

3.  Cross-section  of  arm  with  ambulacral  feet,     x  4. 

4.  Ambulacral  ossicles,  dissected  out.      x  2. 

5.  Spines  from  aboral  surface,      x  10. 

OBSERVATIONS  ON  THE  LIVING  ANIMAL 

Each  student  should  be  provided  with  a  soup-plate  full  of  salt  water. 

1.  Observe  the  eyes,  the  ambulacral  feet  and  their  sucking  disks, 
the  gills  upon  the  back.     Has  the  starfish  strict  radial  symmetry? 

2.  Note  the  method  of  locomotion  by  ambulacral  feet.     With  the 
aid  of  a  diagram  show  what  takes  place  in  a  single  foot. 


358  ZOOLOGY 

3.  Invert  the  starfish  ;  observe  and  record  the  changes  undergone  in 
reassuming  the  normal  position. 

TOPICS    FOR    FURTHER    STUDY 

1.  Habitat  of  starfish.  2.  Food  and  economic  importance.  3.  Gen- 
eral history  of  development.  4.  Allied  forms;  Solaster  and  other 
starfishes,  brittle  stars,  sea-urchins,  holothurians,  crinoids. 

XIV.     HYDRA 

This  exercise  requires  the  use  of  a  lens. 

To  obtain  Hydra  it  will  be  necessary  to  search  carefully  in  fresh- 
water pools.  Lemna  together  with  sticks  and  grass  should  be 
collected  from  the  pools  and  put  into  an  aquarium.  The  Hydras, 
which  are  attached  to  these  objects,  will  then  usually  migrate  in  the 
course  of  a  few  days  to  the  light  side  of  the  vessel,  where  they  can 
be  easily  found.  Hydras  can  be  kept  readily  throughout  the  entire 
winter  in  a  large  glass  jar  containing  Lemna  and  other  plants,  and 
Entomostraca  for  food.  All  the  following  exercises  can  be  done  on 
the  living  animal,  and  either  the  brown  species  (H.  fused)  or  the 
green  species  (H.  viridis)  may  be  employed. 

DRAWINGS 

(From  living  individuals) 

1.  Side  view  of  a  single  Hydra,  not  budding,      x  10. 

2.  Side  view  of  a  Hydra  with  buds,      x  10. 

(Optional,  requires  compound  microscope.)  Draw  one  of  the  ten- 
tacles of  Hydra,  showing  discharged  and  undischarged  nettling 
capsules,  x  300. 

OBSERVATIONS  ON  THE  LIVING  ANIMAL 

Each  student  should  be  provided  with  the  following :  (1)  4-inch 
battery  jar;  (2)  2-inch  Stender  dish;  (3)  vial  containing  5%  sugar 
solution ;  (4)  vial  containing  5  %  acetic  acid-;  (5)  a  few  Daphnias  in 
a  watch-glass ;  (6)  pipette ;  (7)  needle ;  (8)  watch-glass ;  (9)  paste- 
board box  of  a  slightly  larger  size  than  the  battery  jar  and  with  a 
vertical  slit  half  an  inch  wide  along  one  side. 
Place  a  Hydra  in  a  watch-glass  full  of  water. 


LABORATORY   WORK,   XV  359 

1.  Touch  the  tentacles  of  the  Hydra  with  a  needle.     What  move- 
ments? 

2.  Drop  cautiously  and  at  intervals  of  a  few  minutes  upon  the  sur- 
face of  the  water  over  the  tentacles  of  the  Hydra  a  drop  of  water,  of 
sugar  solution,  of  acid.     What  differences  in  the  movements? 

3.  Bring  a  Daphnia  (previously  stranded)  on  the  end  of  a  needle 
to  the   tentacles   of  the   Hydra.     Note  the   result.      With   another 
Hydra,  use  a  bit  of  plant  tissue. 

4.  (This  and  the  following  experiment   must  extend  through   several 
days.)     Place  a  Hydra  in  a  watch-glass  with  a  little  water,  and  .by 
means  of  the  needle  and  a  penknife  cut  it  into  two  or  three  pieces. 
Let  the  pieces  expand  and  draw  them.      By  means  of  a  clean  pipette 
place  the  pieces  in  the  small  Stender  dish,  in   clean  water.      Draw 
the  pieces  again  after  twenty-four  hours,  and  after  a  longer  period  if 
necessary. 

5.  Place  in  a  4-inch  battery  jar  full  of  water  containing  Lemna  and 
Entomostraca  two  or  three  large,  budding,  green  Hydras.     Cover  the 
jar  with  the  box,  placing  the  slit  next  to  the  window.      Note  at  short 
intervals  for  two  weeks  the  position  and  number  of  Hydras  in  the  jar. 

TOPICS    FOR    FURTHER    STUDY 

1.  The  habitat  and  food  of  Hydra.  2.  Other  fresh-water  or  brack- 
ish-water hydroids  (Cordylophora,  Limnocodium)  and  the  origin 
of  fresh-water  Hydrozoa.  3.  Marine  hydroids  (Obelia,  Sertularia, 
etc.)  and  their  jellyfishes.  4.  Sea-anemones  and  corals.  5.  Corals 
as  island  builders.  6.  Budding  and  the  formation  of  colonies  among 
animals.  7.  Division  of  labor  in  colonies.  8.  Regeneration  in 
polyps. 

XV.     PARAMECIUM 

This  exercise  requires  the  use  of  the  compound  microscope. 

Two  or  thre'e  weeks  before  Paramecia  are  needed,  put  hay  and 
decaying  leaves  in  stagnant  water  and  keep  in  a  warm  room.  When 
the  water  has  become  foul,  Paramecia  have  probably  appeared.  To 
prevent  the  Paramecia  on  the  slide  from  moving  too  rapidly,  it  is 
advisable  to  put  them  in  a  2.5  %  solution  of  gelatine  in  water.  Study 
first  with  the  low  power,  then  with  the  high.  To  bring  out  the 


360  ZOOLOGY 

nuclei  in  the  living  animal,  run  a  5%  or  10%  aqueous  solution  of 
methyl  green  under  the  cover-glass  by  placing  the  solution  at  one 
edge  of  the  cover-glass  and  drawing  it  under  by  filter  paper  placed  at 
the  opposite  edge.  To  stain  the  plasma,  a  little  iodine  may  be  added ; 
this  will  kill,  with  explosion  of  trichocysts. 

DRAWING 
{From  observations  on  several  individuals) 

Whole  animal,  showing  shape  of  body,  cilia,  vestibule,  food- 
globules,  non-contracting  vacuoles,  contracting  vacuoles,  nucleus, 
trichocysts.  x  about  200. 

OBSERVATIONS  ON  THE  LIVING  ANIMAL 

Each  student  should  be  provided  with  the  following:  (1)  vial 
containing  beef  extract ;  (2)  vial  containing  finely  powdered  car- 
mine in  water ;  (3)  common  salt ;  (4)  pipette ;  (5)  filter  paper. 

1.  Is  the  protoplasm  in  the  body  of  Pararnecium  quiet  or  moving? 

2.  Place  Pararnecium  in  a  drop  of  the  gelatine  solution.      Cover 
with  cover-glass.     Run  carmine-water  under  the  cover-glass;  select  a 
quiet  individual  and  observe  how  the  carmine   grains   pass   by   it. 
Indicate  by  arrows  placed  outside  the  periphery  of  the  drawing  the 
direction  of  movement  of  the  carmine.      What  do  you  infer  concern- 
ing the  movement  of  the  cilia?     Do  the  grains  whirl  as  much  about 
a  moving  individual  as  about  a  quiet  one  ?     Can  you  explain  ?     Why 
are  not  all  the  Paramecia  carried  off  by  the  current  when  carmine  is 
run  under  the  cover-glass  ? 

3.  Place  upon  a  clean  glass  slide  a  drop  of  water  containing  Para- 
mecia.    When  they  are  uniformly  distributed,  put  a  few  grains  of 
common  salt  in  the  centre  of  the  drop.       After  a  few  seconds  observe 
and  draw  the  distribution  of  the  organisms.     How  is  the  result  to 
be  interpreted? 

4.  Place  upon  the  glass  slide  a  drop  of  water  containing  Paramecia; 
by  means  of  a  pipette  (drawn  to  a  fine  point),  add  a  drop  of  £  %  to 
T^  %  acetic  acid ;  after  two  or  three   minutes  draw   the   distribution 
of  the  Paramecia.     How  do  reactions  to  acids  and  to  salts  compare  ? l 

!See  H.  S.  Jennings,  American  Journal  of  Physiology,  May,  1899,  and 
American  Naturalist,  May,  1899. 


LABORATOEY    WORK,  XVI  361 

5.  Under  a  moderate  power  observe  the  reactions  of  Paramecium 
when  it  comes  to  the  salt  or  acid. 

TOPICS    FOR    FURTHER    STUDY 

1.  How  the  Infusoria  get  into  the  aquarium.  2.  The  habitat  and 
food  of  Paramecium.  3.  Allies  of  Paramecium :  Stentor,  Vorti- 
cella,  Carchesium,  Euglena,  the  Suctoria,  Amoeba,  the  Gregarinidse. 
4.  Economic  importance  of  Amoeba  and  the  Gregarinidae.  5.  Repro- 
duction of  Paramecium. 


XVI.    SMELT    (Osmerus  mordax} 

Various  other  bony  fishes  may  replace  the  smelt,  e.g.  brook  trout 
(Salmo  fontinalis),  lake  herring  or  white  fish  (Coregonus),  perch 
(Perca). 

DRAWINGS 

1.  Whole  animal,  from  left  side,  fins  extended,  showing  number  of 
fin  rays,  position  of  lateral  line,  mouth,  tongue,  teeth,  nostrils,  anus, 
urinary  openings,      x  1  to  2. 

2.  Side  view  of  a  few  trunk  segments   as  seen  after  removal   of 
skin. 

3.  Ventral  view  of  head,  gill  cover  removed,  mouth  open,  probes 
passing  from  mouth  through  each  of  the  gill  slits.     Show  teeth  and 
slime-glands,      x  2  to  3. 

4.  Dorsal  view  of  head,  showing,  when  possible,  form  of  brain  seen 
through  brain  case,      x  2. 

5.  Cross-section  (5  mm.  thick)  of  whole  animal  in  front  of  anus 
and  behind  dorsal  fin.     Name  organs  as  instructed  by  teacher. 

6.  Lateral  view    of    vertebra,   from   the  section   mentioned   in   4, 
isolated  by  boiling. 

QUESTIONS  ON  EXTERNAL  ANATOMY 

1.  How  many  rows  of  scales  are  there  above  the  lateral  line ;  how 
many  below  ? 

2.  How  many  segments  behind  the  head?    Is  this  number  constant? 
(Compare  with  two  other  individuals.) 


362  ZOOLOGY 

3.  What  special  fitness  in  the  form  of  the  body  to  the  habits  of  the 
fish? 

OBSERVATIONS  AND  EXPERIMENTS  ON  THE  LIVING  ANIMAL 

1.  Role  of  fins  in  locomotion.    By  means  of  a  cotton  string  wrapped 
around  body,  bind  down  the  pectoral  fins   and  replace   in  water; 
result?     Bind  ventrals  similarly;  result?     Wrap  string  around  tail 
and  replace  in  water;  result?    Conclusions? 

2.  How  dp    the   movements    of    the    caudal  fin  cause  the  fish  to 
progress? 

TOPICS    FOR    FURTHER    STUDY 

1.  Habitat  and  food  of  the  species.  2.  Distribution  and  economic 
importance.  3.  Allied  species :  salmon,  trout,  white  fish.  4.  Other 
groups  of  fresh-water  bony  fishes :  the  darters,  perch,  sunfish,  stickle- 
backs, silversides,  minnows,  pike,  shad,  suckers,  catfish,  eels.  5. 
Other  kinds  of  fish  :  Amphioxus,  lampreys,  sturgeons,  spoonbills, 
garpike,  Amia.  6.  The  ontogeny  of  a  bony  fish.  7.  The  migrations 
of  fish.  8.  Artificial  breeding  and  fish-hatching  stations. 

XVII.     NEWT    (Diemyctylus  viridescens) 

For  this  species  may  be  substituted  the  small  spring  or  brook 
salamanders  (Desmognathus  and  Spelerpes),  Amblystoma,  or  even 
Necturus.  The  small  size  of  the  brook  salamanders  makes  them 
especially  useful  for  external  study  and  preservation  in  alcohol. 

DRAWINGS  (of  convenient  size) 

1.  Entire  animal. 

2.  View  of  the  left  side  of  head,  mouth  open. 

3.  Left  fore  foot,  dorsal  surface. 

4.  Left  hind  foot,  palmar  surface. 

5.  Form  of  front  lateral  teeth,      x  10. 

QUESTIONS  ON  EXTERNAL  ANATOMY 

1.  Which  is  the  thumb  side  of  hind  foot? 

2.  Are  the  spots  on  the  body  arranged  according  to  any  law  ? 

3.  Are  there  two  movable  eyelids  ? 

4.  Where  is  the  ear  ? 


LABORATORY   WORK,   XVIII  363 

OBSERVATIONS  ON  THE  LIVING  ANIMAL 

1.  How  are  the  movements  of  appendages  and  tail  correlated  in  lo- 
comotion (a)  on  land,  (6)  in  water  ?    Diagrams. 

2.  Observe  the  instincts  of  the  animal  when  placed  in  a  box  of 
earth  Q  damp  and  ^  dry)  lighted  on  one  side  from  the  window  arid 
strewn  with  leaves  and  stones. 

TOPICS    FOR    FURTHER    STUDY 

1.  Habitat  and  food  of  the  species  studied.  2.  Distribution  of 
Amphibia.  3.  Allied  organisms  in  the  United  States:  Desmogna- 
thus,  Plethodon,  Amblystoma,  Amphiuma,  Necturus,  Siren ;  their 
distribution  and  habitats.  4.  Experiments  upon  changing  Axolotl 
into  Amblystoma.  5.  Egg-laying  of  Urodela  and  general  form- 
changes  accompanying  development. 

XVIII.     LIZARD    (Anolis  carolinensis} 

This  may  be  replaced  by  any  other  species.  Where  live  lizards 
cannot  be  easily  obtained,  substitute  a  snake  or  tortoise  and  make 
appropriate  changes  in  the  following  outline. 

DRAWINGS 

1.  Entire  animal,  dorsal  view,      x  1  to  3. 

2.  Dorsal  view  of  head,  showing  scales,  especially  the  parietal  scale, 
x  3. 

3.  Left  side  of  head  ;  mouth  open,  tongue  exposed,     x  3. 

4.  Left  fore  foot,  dorsal  aspect,      x  3. 

5.  Left  hind  foot,  palmar  aspect,      x  3. 

6.  Outline  of  front  lateral  teeth,      x  10. 

7.  Outline  of  scales  on  ventral  side  at  base  of  tail,      x  10. 

8.  Outline  of  scales  on  back,      x  10. 

QUESTIONS  ON  EXTERNAL  ANATOMY 

1.  Which  is  the  thumb  side  of  the  fore  foot  ?    Why  ?     Of  the  hind 
foot?     Why? 

2.  What  is  the  function  of  the  structures  on  the  pads  of  the  toes  ? 


364  ZOOLOGY 

3.  Where  is  the  ear-drum? 

4.  ( This  may  best  be  studied  on  the  living  animal.}     Is  there  a  nicti- 
tating membrane,  as  in  birds? 

OBSERVATIONS  ON  THE  LIVING  ANIMAL 
Each  student  should  be  provided  with  a  set  of  Bradley's  color  cards. 

1.  Which  eyelid  is  more  used  in  winking,  the  upper  or  the  lower  ? 

2.  Locomotion  :    Order  of  movement  of  legs  ;  correlation  of  leg  and 
tail  movement. 

3.  Change   of  color :     Effect   of  colored  backgrounds    (Bradley's 
colors1),  of  warming  by  holding  in  the  hand,  of  stroking  the  back. 

TOPICS    FOR    FURTHER    STUDY 

1.  Habitat,  food,  and  distribution  of  Anolis.  2.  Common  lizards  of 
the  region,  if  any.  3.  Other  interesting  lizards,  such  as  the  chameleon, 
the  blind  worm  (Anguis),  the  Gila  monster  (Heloderma),  lizards  of 
Europe  (LacQrta),  fossil  Reptilia. 

XIX.     "ENGLISH"   SPARROW  (Passer  domesticus) 

This  introduced  bird  can  be  obtained  in  most  large  cities  in  sufficient 
numbers.  Recently  killed  birds  are  the  most  favorable  for  laboratory 
work.  Subjection  to  fumes  of  carbon  disulphide  is  a  useful  precau- 
tion against  bird  lice. 

DRAWINGS 

1.  Side  view  (left).     Name  parts.     Natural  size. 

2.  Head  and  bill,  side  view,  mouth  open,  showing  tongue,     x  2. 

3.  Foot  (left),  dorsal  surface,      x  2. 

4.  Foot  (left),  palmar  surface,      x  2. 

5.  Contour  feather  (from  tail),      x  2. 

6.  Plumage  feather,      x  3. 

7.  The  egg.     x  2. 

QUESTIONS  ON  EXTERNAL  ANATOMY 

1.  Color  of :  (a)  eye  ;  (6)  bill;  (c)  feet ;  (d)  throat;  (e)  breast; 
(/)  belly ;  (#)  crest ;  (//)  side  of  head  ;  (i)  back  ;  (&)  wing  ;  (/)  rump  ; 
(m)  tail  feathers  ? 

1  Milton  Bradley  Company,  Springfield,  Mass. 


LABORATORY   WORK,   XX  365 

2.  Number  of  tail  feathers  ? 

3.  Number  of  primaries  ? 

4.  How  many  segments  in  the  leg  ;    in  the  wing  ? 

TOPICS    FOR    FURTHER    STUDY 

1.  The  introduction  of  the  "  English  "  sparrow  into  America  and 
similar  instances  of  introduction  and  spread  of  exotic  species.  2.  The 
food  and  habits  of  the  "  English "  sparrow  in  America.  3.  The 
native  sparrows.  4.  Other  groups  of  birds  :  thrushes,  bluebirds,  tit- 
mice, nuthatches,  creepers,  wrens,  warblers,  tan  age  rs,  swallows,  wax- 
wings,  vireos,  shrikes,  larks,  orioles,  crows,  flycatchers ;  parrots  and 
cockatoos;  toucans  and  cuckoos,  kingfishers  ;  woodpeckers,  humming- 
birds, swifts,  goatsuckers ;  pigeons ;  grouse  and  fowl ;  ostriches ; 
waders  ;  swimmers,  and  divers.  5.  The  migrations  of  birds  ;  migra- 
tion data.  6.  Flight  of  birds.  7.  The  food  and  economic  importance 
of  birds.  8.  The  preservation  of  birds.  9.  Fossil  birds. 


XX.     MOUSE  (Mus  mustelus) 

Tame  mice  may  be  obtained  from  bird  fanciers  in  most  of  our  large 
cities.1  They  can  be  kept  in  the  laboratory  indefinitely.  Galvanized 
wire  cages  with  doors  and  galvanized  iron  bottoms  are  serviceable. 
Supply  with  cotton,  hay,  or  excelsior  for  a  nest.  Keep  at  an  equa- 
ble, moderate  temperature,  and  pay  great  attention  to  cleanliness. 
Feed  on  oats  and  bread,  with  occasional  fruit,  carrot,  and  cooked  meat. 

DRAWINGS 

1.  Side  view  (left).     Name  parts.     Natural  size. 

2.  Head,  dorsal  view,      x  1.5. 

3.  Fore  foot  (left),  dorsal  surface,      x  2. 

4.  Fore  foot  (left),  palmar  surface,      x  2. 

5.  Hind  foofr  (left),  dorsal  surface,      x  2. 

6.  Side  view  of  skull,     x  3. 

7.  Upper  surface  of  lower  jaw  showing  teeth,      x  3. 

8.  Incisor  tooth  (free),      x  10. 

i  Mr.  H.  C.  Ostendorf ,  420  N.  Eutaw  St.,  Baltimore,  has  been  found  reliable 
by  the  writer,  and  keeps  a  stock  on  hand. 


366  ZOOLOGY 


OBSERVATIONS  ON  THE  LIVING  ANIMAL 

Each  student,  or  set  of  students,  should  be  provided  with  the 
following :  (1)  a  cage  of  wire  netting  about  8  inches  cube,  with  a 
door  on  top;  (2)  a  tin  box  or  small  cigar  box,  closed  except  for 
a  f-inch  hole  and  small  enough  to  be  put  into  the  cage. 

1.  Enumerate  the  kinds  of  activities  of  the  mouse  in  the  cage. 

2.  Bring  a  piece  of  toasted  cheese  to  one  side  of  cage.     Note  any 
change  of  movements. 

3.  Place  the  small  box  in  the  cage.     Note  the  actions  of  the  mouse. 
Does  he  go  directly  to  the  hole  or  does  he  find  it  by  accident,  or 
otherwise  ? 

TOPICS    FOR    FURTHER    STUDY 

1.  The  distribution  of  mice  and  rats.  2.  The  habits  of  rats  and 
mice.  3.  The  food  of  mice.  4.  The  races  of  tame  mice.  5.  Other 
rodents.  6.  Other  mammals  :  the  monotremes,  marsupials,  edentates, 
Cetacea,  Ungulata,  Insectivora,  Carnivora,  Cheiroptera,  and  Primates. 
7.  The  descent  of  man. 

XXL  DEVELOPMENT  OF  THE  FROG'S  EGG 

The  eggs  of  toads  and  even  of  Urodela  may  be  substituted, 
although  this  outline  accords  closely  with  Anura  only.  Frog-spawn 
may  be  obtained  in  April  in  ponds  and  marshes  as  jelly-like  masses 
containing  the  eggs.  Toad-spawn  occurs  as  threads  intertwining 
with  the  grass  at  the  margins  of  shallow  pools.  Eggs  may  be 
obtained  from  animals  in  captivity  by  placing  breeding  males  and 
females  in  a  large  glass  aquarium  in  the  laboratory.  The  eggs  should 
be  studied  shortly  after  being  laid  and  at  various  later  periods. 

DRAWINGS 

(  While  it  is  desirable  that  these  be  made  from  the  living  eggs,  they  may 
be  made  from  eggs  .killed  in  hot  water  at  80°  C'.) 

1.  A  bit  of  spawn  with  a  few  eggs  in  place,      x  2. 

2.  Isolate  eggs,  watch  and  draw  various  stages  till  hatching.     The 
series  should  include  as  many  of  the  following  stages  as  possible  : 
cleavage,  inorula,  blastopore  formation,  medullary  folds,  gill  covers, 


METHODS   OF  EXAMINATION  367 

gills,  newly  hatched  tadpole,  tadpole  several  days  after  hatching. 
(Optional,  a  series  of  tadpoles  showing  metamorphosis.)  x  15  to  20. 
(Keep  a  record  of  the  time  —  day,  hour,  minute  —  when  each  stage 
was  drawn.) 

EXPERIMENTS 

1.  Keep  some  of  the  same  spawn  in  a  refrigerator  for  ten  days, 
then   draw  and  compare  with  the  eggs  kept  at  normal  temperatures 
for  the  same  length  of  time. 

2.  At  the  time  of  formation  of  neural  folds,  free  an  embryo  from 
the  albumen,  and  add  carmine  grains  to  the  (shallow)  water.      Note 
the  direction  of  currents  and  motion  of  cilia. 

3.  Amputate  the  tail  of  a  newly  hatched  larva  and  observe  the 
result  after  a  week  or  two. 

4.  Find  the  (approximate)  specific  gravity  of  a  tadpole  by  placing 
one  or  two  in  each  of  the  following  solutions  of  gum  arabic  in  water : 

Per  cent  by  weight,  33  16.5      11          8.2        3.3        1.65 

Specific  gravity,         1.11+     1.06      1.037  1.028     1.011     1.006 

The  solution  in  which  they  tend,  when  motionless,  neither  to  rise 
nor  fall  is  of  their  specific  gravity.  Repeat  with  tadpoles  just  hatched 
and  with  those  one  week,  two  weeks,  three  weeks,  and  four  weeks 
old.1 

TOPICS    FOR    FURTHER    STUDY 

1.  Effect  of  heat  and  light  upon  development.  2.  Capacity  of 
organisms  for  healing  and  regeneration.  3.  Postembryonic  develop- 
ment of  the  frog,  Arnblystoma,  and  Necturus.  4.  General  laws  of 
development.  5.  Development  of  the  chick.  (This  should  be 
illustrated  by  opening  several  eggs  at  various  stages  of  development.) 


It  may  interest  teachers  to  have  reproduced  here  the  examination 
requirements  of  two  universities  which  are  exactly  covered  by  the 
preceding  outline :  — 

1  See  S.  R.  Williams  in  the  American  Naturalist,  February,  1900,  p.  98. 


368  ZOOLOGY 


I.  METHOD  OF  EXAMINATION  IN  ZOOLOGY  FOR  ADMISSION 
TO  THE  LAWRENCE  SCIENTIFIC  SCHOOL,  HARVARD 
UNIVERSITY. 

The  candidate  is  required  to  pass  both  a  written  and  a  laboratory 
examination.  The  written  examination  will  test  the  range  and  thor 
oughness  of  his  knowledge  of  the  subject.  The  laboratory  examina- 
tion will  test  his  skill  in  observation  and  experimentation,  and  his 
ability  to  apply  names  properly  to  the  parts  of  the  organisms  studied. 

At  the  time  of  the  written  examination  the  candidate  must  present 
the  original  note-book  containing  (with  dates)  the  notes  and  drawings 
he  has  made  in  the  course  of  his  laboratory  work,  and  bearing  the 
endorsement  of  his  teacher,  certifying  that  the  book  is  a  true  record 
of  the  pupil's  own  observations  and  experiments.  An  index  of  sub- 
jects should  be  appended. 


II.  METHOD  OF  EXAMINATION  IN  GENERAL  BIOLOGY  (ZOOLOGY 
AND  BOTANY)  FOR  ADMISSION  TO  THE  JUNIOR  COLLEGES, 
THE  UNIVERSITY  OF  CHICAGO. 

The  candidate  applying  for  admission  credit  in  General  Biology 
will  be  required  :  (a)  To  submit  to  the  examiner  a  note-book  consist- 
ing of  drawings  and  descriptions  of  the  animals  and  plants  studied.  It 
is  recommended  that  studies  of  at  least  fifteen  principal  forms  be 
undertaken,  that  these  studies  be  largely  such  as  do  not  demand  the 
use  of  a  compound  microscope,  and  that  attention  be  given  chiefly  to 
those  organisms  that  can  be  studied  in  a  living  condition ;  (b)  to  de- 
monstrate, in  the  college  laboratory,  under  the  supervision  of  college 
officers,  that  he  possesses  some  power  to  observe  accurately  and  intelli- 
gently. More  stress  will  be  laid  on  correct  observation  and  on  the 
careful  record  thereof,  than  upon  technical  terms ;  (c)  to  answer  in 
writing  a  few  general  questions  about  familiar  animals  and  plants, 
such  as  the  perch,  crayfish,  grasshopper,  moss,  fern,  some  common 
type  of  flowering  plant,  etc. 


APPENDIX    II 

A  LIST  OF  BOOKS  DEALING  CHIEFLY  WITH 
ECOLOGICAL  AND  SYSTEMATIC  ZOOLOGY  OF 
AMERICAN  ANIMALS. 

A.    GENERAL  SYNOPTIC  WORKS 

Leunis,  J.  —  Synopsis  der  Thierkunde.  Dritte  Auflage  von  H.  Ludwig. 
2  Bande.  Hannover.  1883-86. 

This  is  the  nearest  approach  to  a  systematic  manual,  taking  the  place 
in  Zoology  which  Gray's  and  Coulter's  Manuals  do  in  Botany.  It  deals 
chiefly  with  European  species  ;  and  has  not  been  translated. 

Thomson,  J.  A.  —  Outlines  of  Zoology.  3d  edition,  with  332  illustra- 
tions. New  York  :  D.  Appleton  &  Co.  1899.  819  pp. 

An  excellent  condensed  compendium ;  in  which,  however,  the  struc- 
tural side  predominates. 

Riverside  [formerly  Standard]  Natural  History,  edited  by  J.  S.  Kings- 
ley.  6  vols.  large  8°.  Boston  and  New  York  :  Houghton,  Mifflin 
&  Co.  Price  $30. 

The  most  important  large  compendium  written  by  American  authors, 
somewhat  after  the  plan  of  Brehm's  Thiejleben. 

Cambridge  Natural  History,  edited  by  S.  F.  Harmer  and  A.  E.  Shipley. 
New  York  :  The  Macrnillan  Company.  1894. 

An  English  work  of  surpassing  mei'it ;  five  volumes  have  appeared 
but  the  work  is- still  far  from  complete. 

Klassenund  Ordnungen  des  Thierreiches,  edited  (originally)  by  Bronn. 
Leipzig  u.  Heidelberg :  C.  F.  Winter. 

An  extensive  and  thorough  work.     Although  the  whole  work  is  not 
yet  completed,  some  of  the  volumes  are  out  of  date.   The  most  recent  and 
important  are  the  volumes  on  Protozoa,  Porifera,  Co?lenterata,  Vermes, 
Echinodermata,  Crustacea,  Mollusca,  Reptilia,  and  Birds. 
2s  309 


370  ZOOLOGY 

Das  Tierreich.  Eine  Zusammenstellung  und  Kennzeichnung  der  re- 
zenten  Tierfomien.  General  redacteur  :  F.  E.  Schulze.  Berlin  : 
R.  Friedlander  und  Sohn.  1896  — 

A  systematic  account  of  every  known  species,  with  keys  for  their  de- 
termination. An  ambitious  enterprise  which  will  hardly  be  finished 
during  one  generation. 

B.    WORKS  RELATING   TO  ANIMALS   OF  A  PARTICULAR 

HABITAT 

Verrill,  A.  E.  (and  S.  I.  Smith).  —  Report  upon  the  Invertebrate  Ani- 
mals of  Vineyard  Sound  and  the  adjacent  waters,  in  Report  (of 
U.  S.  Fish  Commission)  on  the  Condition  of  the  Sea  Fisheries  of 
the  South  Coast  of  New  England  in  1871  and  1872.  (1873.)  pp. 
205-778. 

An  indispensable  accompaniment  of  the  zoologist  at  the  sea-shore ; 
separate  copies  can  be  purchased  of  dealers  in  scientific  books. 

Emerton,  J.  E.  —  Life  on  the  Seashore.  [For  sale  by  BradJee  AVhid- 
den,  Boston.] 

C.      GENERAL  WORKS    ON    HABITS,   ECOLOGY,   AND 
DISTRIBUTION 

Verworn,  M.  —  General  Physiology.     An  outline  of  the  science  of  Life. 

New  York  :    The   Macmillan  Company.     1899.     615  pp.     Price 

$4.00. 
Morgan,  C.  L. —  Animal  Life  and  Intelligence.     New  York:  Edward 

Arnold.      1891.     503  pp. 
Morgan,  C.  L.  —  Habit  and  Instinct.      New  York:   Edward  Arnold. 

1896.     351  pp. 

The  two  best  books  on  the  topics  considered. 

Lubbock,  J. —  On  the  Senses,  Instinct,  and  Intelligence  of  Animals,  with 

special  reference  to  Insects.     International  Sci.  Ser.,  Vol.  LXIV. 

New  York  :  D.  Appleton  &  Co.     1888. 
Marey,  E.  J.  — Movement.     International  Sci.   Ser.,   LXXIII.     New 

York:  D.  Appleton  &  Co.     1895. 
Poulton,  E.  B.  —  The  Colors  of  Animals.    The  International  Scientific 

Series,  Vol.  LXVII.     New  York:  D.  Appleton  &  Co.     1890. 


BIBLIOGRAPHY:  ANATOMY  AND  EMBRYOLOGY     371 

Semper,  K.  —  Animal  Life  as  affected  by  the  Natural  Conditions  of 
existence.  International  Scientific  Series,  XXX.  New  York: 
D.  Appleton  &  Co.  1881. 

Even  to-day  the  best  book  on  Animal  Ecology. 

Wallace,  A.  R. —  Tropical  Nature.  London  and  New  York:  Macmil- 
lan  &  Co.  1895. 

Wallace,  A.  R.  — Geographical  Distribution  of  Animals.  2  vols.  Lon- 
don :  Macmillan  &  Co.  1879. 

Beddard,  F.  E.  —  Text-book  of  Zoogeography.  Cambridge  (Eng.) 
Scientific  Series.  1895. 


D.    WORKS    DEALING    CHIEFLY    WITH    ANATOMY    AND 
EMBRYOLOGY 

Parker,  T.  J.,  and  W.  A.  Haswell.  —  Text-book  of  Zoology.  2  vols. 
Many  illustrations.  New  York  :  The  Macmillan  Co.  1897. 

Parker,  T.  J.,  and  W.  A.  Haswell.  —  Manual  of  Zoology.  Adapted  for 
use  of  American  Schools  and  Colleges.  563  pp.  327  figs.  New 
York  :  The  Macmillan  Co.  1900. 

Rolleston,  G.,  and  W.  H.  Jackson.  —  Forms  of  Animal  Life.     1888. 

Lang,  A.  —  Text-book  of  Comparative  Anatomy.  Translated  by  Ber- 
nard. 2  vols.  New  York  :  The  Macmillan  Co.  1896. 

Brooks,  W.  K.  —  Handbook  of  Invertebrate  Zoology.  For  laboratories 
and  seaside  work.  Boston  :  S.  E.  Cassino.  1882.  [May  be  pur- 
chased of  Bradlee  Whidden,  Boston.] 

Korschelt,  E.,  and  K.  Heider.  —  Text-book  of  the  Embryology  of  Inver- 
tebrates. 3  vols.  New  York  :  The  Macmillan  Co.  1899. 

Balfour,  F.  M.  —  A  Treatise  on  Comparative  Embryology.  In  2  vols. 
London  :  Macmillan  &  Co.  1880-81. 

Although  decidedly  out  of  date,  yet  gives  the  best  general  discussion 
of  the  subject."' 

Hertwig,  0.  —  Text-book  of  the  Embryology  of  Man  and  Mammals. 

Translated  by  E.  L.  Mark.    New  York :  Macmillan  &  Co.     1892. 
Wilson,  E.  B.  —  The  Cell  in  Development  and  Inheritance.    New  York : 

The  Macmillan  Co.     1896. 


372  ZOOLOGY 


E.    PERIODICALS 

Besides  "  Science  "  and  "  Nature,"  both  published  by  The  Macmillan 
Co.,  New  York,  there  will  be  found  of  especial  interest  to  the  zoology 
student :  — 

The  American  Naturalist.  A  Monthly  Journal  devoted  to  the  Natural 
Sciences  in  their  widest  sense.  Published  monthly  by  Ginn  & 
Co.,  Boston.  Price  $4.00  per  year. 

This  journal  is  publishing  keys  for  the  determination  of  North  Amer- 
ican Invertebrates. 


F.     WORKS   ON    SPECIAL    GROUPS 
INSECTS   IN  GENERAL 

The  Cambridge  Natural  History.  Vols.  V  and  VI.  —  Peripatus,  by  A. 
Sedgwick  :  Myriapods,  by  F.  G.  Sinclair;  Insects,  Parts  I.  and  II., 
by  David  Sharp.  Macmillan  &  Co.,  London  and  New  York. 
1895  and  1899. 

Deals  especially  with  Ecology. 

Comstock,  J.  H.  and  A.  B. — A  Manual  for  the  Study  of  Insects.  Ithaca, 
N.  Y. :  Comstock  Publishing  Co.  1895.  Price  $3.75. 

The  best  systematic  treatise  (with  special  reference  to  economic  en- 
tomology) on  Insects  of  the  United  States,  with  keys  to  families. 

Comstock,  J.  H.  —  An  Introduction  to  Entomology.  Ithaca:  Com- 
stock Publishing  Co.  1888. 

Unfinished,  but  more  detailed  than  the  Manual.  Treats  of  Thysannra, 
Pseudoneuroptera,  Orthoptera,  Physopoda,  Hemiptera,  and  Neuroptera 
only. 

Comstock,  J.  H.  —  Insect  Life.  An  Introduction  to  Nature  Study 
and  a  guide  for  teachers,  students,  and  others  interested  in  out-of- 
door  life.  D.  Appleton  &  Co.  New  York,  1897.  349  pp.  Price 
$2.25. 

Packard,  A.  S. — Entomology  for  Beginners.  Henry  Holt  &  Co., 
New  York.  1888.  Price  $1.40. 

Packard,  A.  S.  —  Half  Hours  with  Insects.  Boston:  C.  E.  Lauriat. 
1881. 


BIBLIOGRAPHY,   I  373 

Smith,  J.  B.  —  Economic  Entomology.  Philadelphia:  J.  B.  Lippin- 
cott  &  Co.  1896.  Price  $2.50. 

Packard,  A.  S.  —  Fifth  Report  of  the  United  States  Entomological 
Commission  [U.  8.  Department  of  Agriculture],  being  a  revised 
and  enlarged  edition  of  Bulletin  No.  7  on  Insects  Injurious  to 
Forest  and  Shade  Trees.  Washington:  Gov't  Printing  Office. 
1890.  928  pp.  306  text  figures  and  40  plates. 

A  valuable  and  inexpensive  treatise ;  can  usually  be  obtained  of  deal- 
ers in  second-hand  books. 

Miall,  L.  C.  —  The  Natural  History  of  Aquatic  Insects.  London  and 
New  York:  Macmillan  &  Co.  1895.  Price  $1.75. 

Lubbock,  John.  —  On  the  Origin  and  Metamorphoses  of  Insects.  Na- 
ture Series.  London  and  New  York  :  Macmillan  &  Co.  1895. 

McCook,  H.  C.  —  Tenants  of  an  Old  Farm.  Leaves  from  the  Note- 
book of  a  Naturalist.  New  York  :  Fords,  Howard  &  Hulbert. 
1885. 

Riley,  C.  V.  —  An  Enumeration  of  the  published  synopses,  catalogues, 
and  lists  of  North  American  Insects.     U.  S.  Dept.  of  Agriculture, 
Division  of  Entomology,  Bull.  No.  19.     1888.     77  pp. 
A  very  valuable  bibliography. 

Riley,  C.  V.  —  Directions  for  Collecting  and  Preserving  Insects. 
Smithsonian  Institution,  Washington,  D.  C.,  1892.  Price  25  cents. 


I.     ORTHOPTERA,  NEUROPTERA,  HEMIPTERA,  ETC. 

Scudder,  S.  H.  —  Guide  to  the  Genera  and  Classification  of  the  North 

American  Orthoptera  found  north  of  Mexico.      Cambridge:  E. 

W.  Wheeler.     1897.     89  pp. 
Scudder,   S.   H.  —  Revision    of    the    Orthopteran    group    Melanopli 

(Acridiidse),  with  special  reference   to  North  American  forms. 

Proceedings  XL  S.  National  Museum,  XX.     pp.  1-42.1.      Plates 

1-26.     1897. 
Calvert,  P.  P.  —  Catalogue    of    the    Odonata   (Dragon-flies)    of  the 

vicinity  of  Philadelphia,  with  an  introduction  to  the  study  of 

this  group  of  insects.     Trans.  American  Entomological   Society, 

Philadelphia.     Price  $1,00, 


3T4  ZOOLOGY 

Hagen,  H.  —  Synopsis  of  the  Neuroptera  of  North  America,  with  a 
list  of  South  American  species.  Smithsonian  Miscellaneous 
Collections.  Washington,  D.  C.  1861. 

Banks,  N.  —  A  Synopsis,  Catalogue,  and  Bibliography  of  the  Neu- 
ropteroid  Insects  of  Temperate  North  America.  Trans.  Ameri- 
can Entomological  Society,  Philadelphia.  [Sec'y  Amer.  Entom. 
Soc.  Price  $1.00.] 

Osborn,  H.  —  Classification  of  Hemiptera.  Entomologica  Americana. 
Vol.  I.,  pp.  21-27.  1885. 


II.  LEPIDOPTERA  AND  HYMENOPTERA 

Scudder,  S.  H.  —  Brief  Guide  to  the  Commoner  Butterflies  of  the 
Northern  United  States  and  Canada.  Henry  Holt  &  Co.,  New 
York.  1893.  Price  $1.25. 

French,  G.  H.  —  The  Butterflies  of  the  Eastern  United  States.  For 
the  use  of  classes  in  Zoology  and  private  students.  Philadelphia : 
Lippincott  &  Co.  1886. 

Scudder,  S.  H.  —  The  Butterflies  of  the  Eastern  United  States  and 
Canada,  with  special  reference  to  New  England.  3  vols.  Cam- 
bridge, Mass.  Published  by  the  author.  1889. 

Edwards,  W.  H.  —  The  Butterflies  of  North  America.  Boston : 
Houghton,  Mifflin  &  Co. 

Holland,  W.  J.  —  The  Butterfly  Book.  A  popular  guide  to  a  knowl- 
edge of  the  butterflies  of  North  America,  with  48  plates  in  color 
photography.  New  York :  Doubleday  &  McClure  Co.  1898. 

Knobel,  E.  —  The  Day  Butterflies  and  Dusk  Flies  of  New  England; 
how  to  find  and  know  them  (1895);  also  The  Night  Moths  of 
New  England;  how  to  determine  them  readily  (1895).  Boston: 
Bradlee  Whidden. 

Cresson,  E.  T.  —  Synopsis  of  the  Families  and  Genera  of  the  Hyrae- 
noptera,  North  of  Mexico,  together  with  a  catalogue  of  the 
described  species  and  bibliography.  Trans.  Amer.  Entom.  Soc., 
Suppl.  vol.,  Pt.  I.,  1887.  [Sec'y  Amer.  Entomological  Society, 
Philadelphia.  Price  $3.00.] 

Lubbock,  J.  —  Ants,  Bees,  and  Wasps.  Internat.  Sci.  Series,  Vol. 
XLII.  New  York  :  D.  Appleton  &  Co.  1882. 


BIBLIOGRAPHY,    VI  375 


III.  COLEOPTERA 

LeConte,  J.  L.,  and  G.  H.  Horn.  —  Classification  of  the  Coleoptera  of 
North  America.  [Can  be  purchased  of  the  Secretary  of  the 
American  Entomological  Society,  Philadelphia.  Price  $2.50.] 

Hoffmann,  E.  —  The  Young  Beetle  Collector's  Handbook.  New  York : 
The  Macmillan  Company.  1897.  178  pp.,  20  color  plates. 

This  book  deals  with  European  species ;  but  many  are  closely  related 
to  ours. 

Knobel,  E.  —  Beetles  of  New  England  and  their  kind.  A  guide  to 
know  them  readily.  Boston  :  Bradlee  Whidden.  1895. 

IV.     DIPTERA 

Williston,  S.  W.  —  Manual  of  North  American  Diptera.  Second 
Edition,  1896.  Jas.  T.  Hathaway,  New  Haven,  Conn.  Price 
$2.25. 

Knobel,  E.  —  The  Mosquitoes,  Gnats,  Crane-flies,  Midges,  and  Flies 
of  the  Northern  States.  Boston  :  Bradlee  Whidden.  1897. 

V.     MYRIAPODA 

Bollman,  C.  H.  —  The  Myriapoda  of  North  America.  Bulletin  U.  S. 
National  Museum,  No.  46.  1893. 

VI.  ARACHNOIDEA 

Emerton,  J.  H.  —  The    Structure    and    Habits   of   Spiders.      Salem, 

Mass.     1878.     Price  $1.50. 
Emerton;  J.  H.  —  New  England  Spiders  [of  various  Families].      In 

Transactions  Connecticut  Academy,  New  Haven. 
Peckham,  G.  W.  and  E.  G.  —  North  American  Spiders  of  the  Family 

Attidse.      Transactions  Wisconsin    Academy    of    Science,    Arts, 

and  Letters,- Madison,  Wis.    Vol.  VII.,  1888.     256  pp.,  2  plates. 
Peckham,  G.  W.  and  E.  G.  —  Some    Observations    on    the    Mental 

Powers  of  Spiders.     Journal  of  Morphology,  Vol.  L,  Dec.,  1887. 
McCook,    H.    C.  —  American    Spiders   and    their   Spinning   Work:    a 

Natural  History  of  the  Orb-weaving  Spiders  of  the  United  States, 

with  Special  Regard  to  their  Industry  and  Habits.    3  vols.  4°, 


376  ZOOLOGY 

1889-93;  372  +  479  +  406  pp.;  353  +  401  wood  cuts;  35  plates. 
Philadelphia :  published  by  the  author  [Academy  Nat.  Science, 
Philadelphia]. 

Very  valuable  and  readable  treatise. 

McCook,   H.   C.  —  The  Natural  History  of  the  Agricultural   Ant   of 

Texas.     Philadelphia,  1879. 
Kraepelin,  K.  —  Scorpiones   and   Pedipalpi.     Das   Tierreich,   8.  Lie- 

ferung.     Berlin  :  R.  Friedlander  und  Sohn.    1899. 
Weed,  C.  M.  —  A    Descriptive    Catalogue    of    the    Harvest   Spiders 

(Phalangiidse)    of   Ohio.      Proc.  U.  S.  National   Museum,  Vol. 

XVI.,  pp.  543-563,  3  plates.     1893. 

CRUSTACEA 

Stebbing,  T.  R.  R.  —  A  History  of   Crustacea,  Recent  Malacostraca. 

International  Scientific  Series,  Vol.  71.     New  York :  D.  Appleton 

&  Co.    1893. 
Rathbun,  R.  —  Natural  History  of  Economic  Crustaceans.  In  Bulletin 

U.  S.  Fish  Commission  for  1889,  pp.  763-830,  plates  260-275  and 

plate  cxxi.    1893. 

VII.    MALACOSTRACA 

Huxley,  T.  H.  — The  Crayfish.     An  Introduction  to  the   Study   of 

Zoology.     International  Scientific  Series,  Vol.  XXVIII.     1880. 
Faxon,  M.  —  A   Revision   of  the   Astacidse.      Part  I.:    The  Genera 

Carnbarus  and  Astacus.     Mem.  Mus.  Comp.  Zool.,  Vol.  X.    No.  4. 

Cambridge,  Mass.     1885.     Ill  pp.,  11  plates. 
Herrick,  F.  H.  —  The  American  Lobster :  A  Study  of  its  Habits  and 

Development.      Bulletin  U.  S.  Fish   Commission,  Vol.  XV.,  for 

1895.     252  pp.,  54  plates.    1896. 
Kingsley,  J.  S.  —  Synopses  of  North  American   Invertebrates:    III. 

The  Caridea  of  North  America;  IV.   Astacoid  and  Thalassinoid 

Crustacea.     American  Naturalist,  Vol.  XXXIII.     Sept.  and  Oct., 

1899. 
Benedict,    J.    E.,   and    Mary  J.    Rathbun.  —  The   Genus    Panopeus. 

Proceedings  U.  S.  National  Museum,  Vol.  XIV.,  pp.  355-385,  5 

plates.     1891. 


BIBLIOGRAPHY,   X  377 

Rathbun,  Mary  J.  —  Catalogue  of  the  Crabs  of  the  Family  Periceridae 

[Spider  Crabs]  in  the  U.  S.  National  Museum.    Proceedings  U.  S. 

National  Museum,  Vol.  XVr,  pp.  231-277 ;  3  plates.     1892. 
Rathbun,    Mary    J.  —  Synopses,  etc.      VII.      The   Cyclometopous    or 

Cancroid  Crabs  of  North  America.     American  Naturalist,  Vol. 

XXXIV.     Feb.  1900. 


VIII.    ENTOMOSTRAC  A 

Herrick,C.  L.,and  C.H.  Turner. — Synopsis  of  the  Entomostraca  of  Min- 
nesota: Copepoda,  Cladocera,  and  Ostracoda.  Geological  and 
Natural  History  Survey  of  Minnesota.  1895. 

Giesbrecht,  W.,  and  0.  Schmeil.    Copepoda  :  I.  Gymnoplea.    Das  Tier- 
reich,  6.  Lieferung.     Berlin  :  R.  Friedlander  und  Sohn.    1898. 
Includes  the  free-swimming  marine  species. 

WORMS 

Cambridge  Natural  History.  Vol.  II.  [Flatworms,  Mesozoa,  N"emer- 
tini ;  threadworms,  Sagitta,  rotifers,  polychset  worms,  earth- 
worms, leeches,  Gephyrea,  Phoronis,  Bryozoa.]  New  York :  The 
Macmillan  Company.  1896. 

IX.    OLIGOCILETA  AND  LEECHES,  GEPHYREA  AND 
BRYOZOA 

Darwin,  Charles.  —  The  Formation  of  Vegetable  Mould  through  the 
action  of  Worms,  with  observations  on  their  Habits.  New  York  : 
D.  Appleton  &  Co. 

Michaelsen,  W.  —  Oligochaeta.  Das  Tierreich,  10.  Lieferung.  Berlin: 
R.  Friedlander  und  Sohn.  1900. 

Davenport,  C.  B.  —  Synopses,  etc.  I.  Fresh-water  Bryozoa.  Ameri- 
can Naturalist,  Vol.  XXXIII,  July,  1899. 

X.     POLYCH^TA  AND  LOWER  WORMS 

Verrill,  A.  E.  —  New  England  Annelida.  Part  I.,  with  Plates  III.-XII. 
Trans.  Connecticut  Academy,  Vol.  IV.,  Pt.  2.  1881. 


378  ZOOLOGY 

Andrews,  E.  A.  —  Report  upon  the  Annelida'  Polychseta  of  Beaufort, 
North  Carolina.  Proc.  U.  S.  National  Museum,  Vol.  XIV.,  pp. 
277-302,  7  plates.  1891. 

Johnson,  H.  P.  —  A  preliminary  Account  of  the  Marine  Annelids  of 
the  Pacific  Coast,  with  Descriptions  of  New  Species.  Proc.  Cali- 
fornia Acad.  of  Sciences,  Vol.  I.,  No.  5.  1897. 

Montgomery,  T.  H.  —  Synopses,  etc.  II.:  Gordiacea  (Hair-worms). 
American  Naturalist,  Vol.  XXXIII.  Aug.,  1899. 

Ward,  H.  B.  —  The  Parasitic  Worms  of  Man  and  the  Domestic  Ani- 
mals, in  Report  for  1894  of  Nebraska  State  Board  of  Agriculture. 
Lincoln,  Neb.  1895. 

XL  AND  XII.    MOLLUSCA 

The  Cambridge  Natural  History  :  Vol.  III. :  Mollusca,  by  A.  H.  Cooke. 
New  York  :  The  Macmillan  Company.  1896. 

Tryon,  G.  W.,  Jr.  —  Structural  and  Systematic  Conchology  :  an  intro- 
duction to  the  Study  of  the  Mollusca.  3  vols.  140  plates.  Philadel- 
phia :  published  by  the  author.  [Price,  $6.00 ;  for  sale  by  S.  R. 
Roberts,  Glen  Ridge,  N.  J.] 

Gould,  A.  A.  —  Report  on  the  Invertebrata  of  Massachusetts.     2d  edi- 
tion, by  Binney.     1870.     52+  pp.     528  figures. 
Devoted  to  Mollusca  and  Tunicata. 

Apgar,  A.  C.  —  Molluscs  of  the  Atlantic  Coast  of  the  United  States, 
south  to  Cape  Hatteras.     [Copies  bound  in  cloth,  for  sale   by 
author,  Trenton,  N.  J.     Price,  $1.00.] 
A  very  convenient  book  for  the  pocket. 

Ingersoll,  Ernest,  and  J.  A.  Ryder.  —  Natural  History  of  Economic 
Molluscs  of  the  United  States.  Bulletin  U.  S.  Fish  Commission 
for  1889,  pp.  687-758,  plates  253-259.  1893. 

RADIATES 

Agassiz,  Elizabeth  C.,  and  A.  Agassiz.  —  Seaside  Studies  in  Natural 
History.  Marine  Animals  of  Massachusetts  Bay.  Radiates. 
Boston  :  Ticknor  &  Fields.  1865. 

Fewkes,  J.  W.  —  An  Aid  to  a  Collector  of  the  Coelenterata  and 
Echinodermata  of  New  England,  with  cuts.  Bull.  Essex  Insti- 
tute, Vol.  XX II  I.,  pp.  1-2.  [Sec'y  Essex  Institute,  Salem.] 


BIBLIOGRAPHY,  XIV  379 


XIII.     ECHINODERMATA 

Agassiz,  A.  —  North  American  Starfishes.  Memoirs  Museum  Com- 
parative Zoology  at  Harvard  College,  Vol.  V.,  No.  1.  1877. 
137  pp.  and  20  plates. 

Agassiz,  A.  —  Revision  of  the  Echini.  Illustrated  Catalogue  of  the 
Museum  of  Comparative  Zoology  at  Harvard  College,  No.  VII.,  2 
Parts.  1872-1873. 

Lampert,.K.  —  Die  Seewalzen  (Holothuroidea).  Eine  Systematische 
Monographic  mifc  Bestimmungs-  und  Verbreitungs-  Tabellen. 
Weisbaden  :  C.  W.  Kreidel.  1885.  4°.  310  pp.,  1  plate. 

Brooks,  W.  K.  —  Handbook  of  Invertebrate  Zoology.  Boston :  Cassino. 
1882. 

Has  an  excellent  chapter  on  the  development  of  Echinodernis. 

XIV.     CtELENTERATES 

Trembley,  A.  —  Memoires  pour  servir  a  1'histoire  d'un  genre  de  Po- 
lypes d'eau  douce  a  bras  en  forme  de  cornes.  Leyden.  1744. 
4°.  323  pp.,  13  plates. 

A  remarkable  memoir  on  Hydra  ;  obtainable  from  European  dealers 
in  second-hand  books. 

Agassiz,  L.  —  Contributions  to  the   Natural   History  of  the  United 

States  of  North  America.    Vols.  III.  and  IV.    Second  Monograph, 

in  five  parts.  —  I.  Acalephs  in  general.  —  II.   Ctenophorae.  —  III, 

Discophorae.  —  IV.  Hydroidse.  —  V.  Homologies  of  the  Radiata. 

With  46  plates.     Boston  :  Little,  Brown  &  Co.    1860,  1862. 
Hincks,  T.  —  A  History  of  the  British  Hydroid  Zoophytes.     2   vols. 

London  :  Van  Voorst.   1868.    Vol.  I.  text,  —  Vol.  II.  plates.    Price 

42s. 
Allman,  G.  J.  —  A   Monograph  of   the   Gymnoblastic   or   Tubularian 

Hydroids:*    London  :  Ray  Society.    1871.     4°.    pp.  450,  23  plates. 
Darwin,  Charles.  —  The  Structure  and  Distribution  of  Coral  Reefs. 

New  York :    D.    Appleton    &   Co.     [First    published,     London, 

1842.] 
Agassiz,  A.  —  A  Visit  to  the  Great  Barrier  Reef  of  Australia  in  the 

Steamer  "  Croydon,"  during  April  and  May,  1896.   Bull.  Museum 


380  ZOOLOGY 

of    Comparative    Zoology    at   Harvard  College,  Vol.  XXVIII. 

April,  1898. 
Bowerbank,  J.  S.  —  A  Monograph  of  the  British  Spongiadae.    4  vols., 

numerous  plates.     London  :  Ray  Society.    1864-1882. 
Hyatt,  A.  —  Guides  for  Science  Teaching.     III.  Commercial  and  Other 

Sponges.     Boston  :  Heath  &  Co.    1893. 
Potts,  Edward. — Contributions  toward  a  Synopsis  of  the   American 

forms  of  Fresh-water  Sponges,  with  descriptions  of  those  named 

by  other  Authors  and  from  all  parts  of  the  World,  with  8  plates. 

Proc.  Acad.  Nat.  Science,  Philadelphia,  1887,  pp.  158-279. 


XV.     PROTOZOA 

Biitschli,  0.  —  Protozoa,  Bronn's  Klassen  und  Ordnungen  des  Thier- 
reiches.  Leipzig  u.  Heidelberg  :  C.  F.  Winter.  1889. 

Kent,  W.  Saville.  —  A  Manual  of  the  Infusoria :  including  a  descrip- 
tion of  all  known  flagellate,  ciliate,  and  tentaculiferous  Protozoa, 
British  and  foreign,  and  an  account  of  the  Organization  and 
Affinities  of  the  Sponges.  2  vols.  and  vol.  of  plates.  London :  D. 
Bogue.  1880-1882. 

Leidy,  J.  —  Fresh-water  Rhizopods  of  North  America.  Washington  : 
Government  Printing  Office.  1879. 

VERTEBRATES  IN  GENERAL 

Jordan,  D.  S.  —  Manual  of  the  Vertebrates  of  the   Northern  United 
States.     5th  Edition.     Chicago  :  McClurg. 
Systematic,  with  keys. 

Kingsley,  J.  S.  —  Text-book  of  Vertebrate  Zoology.  New  York: 
Holt  &  Co.  1899. 

About  equally  devoted  to  Morphology  and  Classification. 

Darwin,  C.  —  The  Variation  of  Animals  and  Plants  under  Domestica- 
tion.    2  vols.,  2d  edition.  New  York :  D.  Appleton  &  Co.     1894. 
Domestic  races  of  various  vertebrates. 

NOTE.  —In  many  States,  the  Geological  Surveyor  Natural  History  Survey 
Reports  contain  lists  of  vertebrates  found  in  the  State. 


BIBLIOGRAPHY,   XVIII  381 


XVI.     PISCES 

Goode,  G.  B.  —  American  Fishes.  A  popular  treatise  upon  the  Game 
and  Food  Fishes  of  North  America,  with  especial  reference  to 
habits  and  methods  of  capture.  New  York  :  Standard  Book  Co. 
1888. 

Jordan,  D.  S.,  and  B.  W.  Evermann. —  The  Fishes  of  North  and  Middle 
America.  Bulletin  U.  S.  National  Museum,  No.  47.  4  parts. 
Washington  :  Gov't  Printing  Office.  1898.  3136  pages  and  atlas. 

An  exceedingly  valuable  work,  full  of  biological  data  ;  with  keys  to 
genera  and  species.    Atlas  not  yet  (1899)  published. 

XVII.  AMPHIBIA 

Gage,  S.  H.  — Life   History  of    the   Vermilion-Spotted   Newt    (Die- 

myctylus  viridescens  Raf.).     American  Naturalist,  Dec.,  1891. 
Ritter,  W.  E.  —  Diemyctylus  torosus  Esch.     The   Life  History  and 

Habits   of  the   Pacific  Coast   Newt.     Proc.  California  Acad.  of 

Sciences.     3d  series.     Zoology.    Vol.  I.,  pp.  73-114.     1897. 
Wilder,  H.  H.  —  Desmognathus  fusca  (Rafinesque)  and  Spelerpes  bili- 

neatus  (Green).   American  Naturalist,  Vol.  XXXIII.,  pp.  231-246. 

March,  1899. 
Kirkland,  A.  H.  —  The   Habits,  Food,   and  Economic   Value  of  the 

American   Toad.     Hatch  Experiment    Station,  Amherst,  Mass., 

Bull.  No.  46.     1897. 
Mivart,  St.  George.  —  The  Common  Frog.     Nature  Series.     London  : 

Macmillan  &  Co.     1881. 
Boulenger,  G.  A.  —  The  Tailless  Batrachians  of  Europe.  London  :  Ray 

Society.    1897-1898. 
Jordan,  E.  0.      The  Habits  and  Development  of  the  Newt.      Jour,  of 

Morphology,  Vol.  VIII.,  No.  2.    1893. 
Sherwood,  W.  L.  —  The  Frogs  and  Toads  found  in  the  Vicinity  of 

New  York."    Proceed.  Linn.  Soc.  of  New  York,  No.  10.     1898. 

XVIII.  REPTILIA 

Agassiz,  L.  —  Contributions  to  the  Natural  History  of  the  United 
States  of  America.  First  Monograph.  II.  North  America  Testudi- 


382  ZOOLOGY 

nata ;  III.  Embryology  of  the  Turtle.     Vol.  2.     Boston  :    Little, 
Brown  &  Co.    1857. 

To  be  obtained  from  dealers  in  second-hand  books. 

Taylor,  W.  E.  —  The  Box-Tortoises  of  North  America.  Proc.  U.  S. 
National  Museum,  Vol.  XVII.,  pp.  573-588.  1895. 

XIX.     BIRDS 

Newton,  Alfred,  and  Hans  Gadow.  —  A  Dictionary  of  Birds.  London  : 
Adam  &  Charles  Black.  1893-1896. 

Coues,  Elliott.  —  Key  to  North  American  Birds.  Boston  :  Estes  & 
Lauriat.  1896.  906  pp. 

Ridgeway,  R. —  A  Manual  of  North  American  Birds.  2d  Ed.  Phila- 
delphia: J.  B.  Lippincott  Co.  1896. 

Chapman,  F.  M.  —  Bird  Life.  A  Guide  to  the  Study  of  our  Common 
Birds.  New  York  :  D.  Appleton  &  Co.  1897. 

Parkhurst,  H.  E.  —  How  to  Name  the  Birds.  New  York :  Charles 
Scribner's  Sons. 

Wright,  Mabel  0.,  and  E.  Coues.  —  Citizen  Bird.  With  111  illustra- 
tions by  L.  A.  Fuertes.  New  York :  The  Macmillan  Co.  1898. 

Besides  these  are  a  score  or  more  good  books  on  American  birds, 
and  guides  to  their  study.    The  foregoing  are  representative. 

XX.     MAMMALIA 

Flower,  W.  H.,  and  Lydekker,  R.  —  An    Introduction  to  the    Study 

of  Mammals,  living  and  extinct.     London  :  Adam  and  Charles 

Black.     1891. 
Lydekker,  R.  —  A  Geographical  History  of    Mammals.      Cambridge 

Geographical  Series.   Cambridge  (Eng.),  at  the  University  Press. 

1886.     [The  Macmillan  Co.,  New  York.     Price  lO.s.  6</.] 
Mivart,  St.  George. — The  Cat.     An  Introduction    to   the   Study  of 

Backboned  Animals.     New  York  :  Scribner's.    1881. 

XXI.     DEVELOPMENT    OF    THE   FROG 

Morgan,  T.  H.  —  The  Development  of  the  Frog's  Egg :  An  Intro- 
duction to  Experimental  Embryology.  New  York :  The  Mac- 
millan Co.  1897. 


APPENDIX  III 

SYNOPSIS   OF   THE   ANIMAL   KINGDOM 

GROUPS  OF  ANIMALS  ARRANGED  APPROXIMATELY 
IN  AN  ASCENDING  SERIES;  WITH  REFERENCES  TO 
EVERY  FAMILY  MENTIONED  IN  THE  MAIN  TEXT; 
AND  WITH  DEFINITIONS  OF  THE  CLASSES  AND 
ORDERS 

NOTE.  —  Owing  to  the  method  employed  in  the  text  of  proceeding  from  a 
type  to  the  allied  groups,  the  systematic  relations  of  the  organisms  considered 
are  of  ten  obscured.  This  synopsis  is  intended  to  make  these  relations  clearer. 
It  can  also  be  used  as  a  systematic  index  of  the  book.  Moreover,  the  student 
can  use  it  in  reviewing  his  knowledge  of  the  text,  and  as  a  key  for  the  deter- 
mination of  the  class  in  which  a  specimen  falls.  The  teacher  can  employ  it  as 
a  guide  to  collecting  illustrative  material;  for  every  family  mentioned  should, 
as  far  as  possible,  be  illustrated  by  specimens  or  good  figures. 

In  the  synopsis  group-names  printed  in  full-face  are  phyla;  in 
LARGE  CAPITALS,  classes ;  in  SMALL  CAPITALS,  orders ;  in 
italics,  families.  Subphyla,  subclasses,  and  suborders  are  indicated 
by  bracketing.  Thus  [CILIATA]  is  a  subclass.  Numbers  in 
parentheses  refer  to  pages  of  the  text. 

PROTOZOA 


Animals  composed  of  a  single  cell ;  or,  if  of  several  cells,  these  are 
of  one  kind. 
rj2/*A^RHIZOPODA.  Protozoa  with  retractile  pspudopodia:  Amceba(227). 

SPOROZOA.      Protozoa  without   appendages;   internal  parasites 
(227). 

FLAGELLATA.     Protozoa  without  cilia  but  with  one  or  more 
flagella  (225). 


384  ZOOLOGY 

INFUSORIA.     Protozoa  with  cilia  or  sucking  tentacles  (222). 

[CILIATA].      Locomotor,   with   cilia:    HOLOTRICHA  (Parame- 
cium,  224);  HETEROTKICHA  (224)  ;  PERITRICHA  :  Vorticella  (225). 
[SUCTORIA].     Sessile,  with  sucking  tentacles  (225). 

CCELENTERATA 

Animals  of  radial  structure,  whose  digestive  cavity  is  lined  by  the 
body-wall  (205). 

[SPONGIARIA] 

Ccelenterata  whose  body-wall  is  perforated  by  incurrent  pores  (205). 

[CNIDARIA] 

Ccelenterata  whose  body-wall  is  not  perforated  by  incurrent  pores, 
and  which  have  nettling  organs  of  some  sort  (205). 

HYDROZOA.  Cnidaria  whose  body  is  composed  of  more  than  two 
rays  and  contains  a  simple  cavity.  HYDROMEDUS.E,  attached  Hydro- 
zoa  in  hydroid  stage ;  medusa  simple  :  Hydroidce  (208)  ;  Hydrocoral- 
lidce  (208)  ;  Tubularidce  (208)  ;  Campanularidce  (209) ;  Trachomedusce 
(Zygodactyla,  212).  SIPHONOPHORA,  a  free  swimming  colony  of 
Hydrozoa  (212). 

SCYPHOZOA.  Cnidaria  with  many  radii,  and  with  radial  parti- 
tions in  cavity  of  body  (214). 

CTENOPHORA.  Cnidaria  with  only  two  radii,  and  rows  of  cilia- 
plates  (219). 

SCOLECIDA 

Animals  of  worm-like  form,  with  bilateral,  unsegmented  body. 

PLATYHELMINTHES.  Bilaterally  symmetrical,  soft-bodied 
animals,  without  true  segmentation  of  the  body  ;  flattened  in  a  dorso- 
ventral  direction,  and  having  body-cavity  filled  with  a  loose  meshwork 
of  cells.  TURBELLARIA,  free-living  flatworms  whose  body  is  cov- 
ered by  cilia ;  alimentary  tract  with  only  one  opening  to  the  exte- 
rior: Planaria  (153).  TREMATODA,  parasitic,  without  cilia  in  the 
adult;  the  mouth  leads  into  a  forked  food-canal  without  anus:  Dis- 
tomum  (153).  CEST.ODA,  elongated  tape-like  intestinal  parasites, 
without  mouth  or  food-canal :  Taenia  (156).  NEMERTINI,  body  more 
or  less  flattened ;  food-canal  with  mouth  and  anus ;  a  separate  pro- 
trusible  proboscis  (158). 


SYNOPSIS  OF  THE  ANIMAL  KINGDOM  385 

NEMATHELMINTHES.  Bilateral,  unsegmented,  round-worms; 
usually  with  alimentary  tract,  mouth,  and  anus  :  Ascaris  (151). 

ROTIFERA.  Small  aquatic  Scolecida,  with  ciliated  band  around 
mouth,  and  a  special  organ  for  attachment,  the  foot;  wheel-animal- 
cules. 

BRYOZOA.  Scolecida  in  which  the  ciliated  band  is  carried  out  on 
a  series  of  tentacles  surrounding  the  mouth ;  form  colonies  by  bud- 
ding. ENDOPROCTA,  Bryozoa  with  head  and  stalk,  and  crown  of  tenta- 
cles surrounding  both  mouth  and  anus  (143).  ECTOPROCTA,  with 
anus  outside  tentacular  corona  (143). 

MOLLUSCA  i 

Animals  with  unsegmented  body  and  without  jointed  appendages. 
Usually  with  a  shell  and  with  a  muscular  organ  of  locomotion,  the 
foot. 

LAMELLIBRANCHIATA.  Mollusca  with  nearly  symmetrical 
body,  leaf -like  gills,  and  a  shell  composed  of  two  valves.  Ledidce 
(187);  Arcidce  (184);  Mytilidce  (184);  Aviculidce  (185);  Pectinidce 
(186)  ;  Ostreidce  (187)  ;  Unionidce  (179)  ;  Cycladidce  (180)  ;  Mactridce 
(182)  ;  VeneridcB  (183)  ;  Myidce  (182)  ;  Solenidce  (182)  ;  Pholadidce 
(181);  Teredidce  (181). 

GASTROPODA.  Mollusca  with  head,  feelers,  and  eyes,  an  un- 
paired foot,  and  a  shell  that  is  univalve  when  present.  AMPHINEURA, 
with  strict  bilateral  symmetry,  no  externally  visible  gills,  and  usu- 
ally a  shell  composed  of  eight  pieces:  Chiton  (171).  PROSOBRANCHI- 
ATA,  with  gills  in  front,  shelled  and  operculate  :  Acmceidce  (170)  ; 
Patellidce  (170) ;  Fissurellidce  (170) ;  Naticidce  (168) ;  Calyptrceidas 
(Crepidula,  169) ;  Littorinidce  (167) ;  Muricidce  (Urosalpinx,  169) ; 
Fasciolariidce  (Fulgur,  168).  OPISTHOBRANCHIATA,  with  gills  behind 
heart;  if  shelled,  without  operculum  ;  ^Eolidiidce  (171).  PULMONATA, 
breathing  by  means  of  lungs,  no  operculum  :  Auriculidce  (165)  ;  Lim- 
nceidce  (166)  ;  Limacidce  (161)  ;  Helicidce  (164)  ;  Pupidce  (165). 

CEPHALOPODA.  Mollusca  with  large  head,  mouth  surrounded 
by  a  circle  of  arms,  and  funnel-shaped  foot.  Argonautidce  (172) ; 
Spirulidce  (172)  ;  Loliginidce  (172)  ;  Nautilidce  (173). 

1  This  classification,  unlike  that  of  the  text,  follows  Cooke  in  his  "  Mol- 
lusca." 

2c 


386  ZOOLOGY 


ECHINODERMATA 

Animals  of  a  prevailingly  radial  structure,  with  intestinal  wall  dis- 
tinct from  body-wall  and  with  calcareous  plates  in  the  skin  (192). 

CR1NOIDEA.  Sessile  Echinodermata,  having  a  cup-shaped  body 
(203). 

ASTEROIDEA.  Star-shaped  Echinodermata,  with  a  furrow  along 
the  under  side  of  the  arms  (193). 

OPHIUROIDEA.  Star-shaped  Echinodermata,  with  ungrooved 
arms  (198). 

ECHINOIDEA.   With  armless,  globular,  or  cake-shaped  body  (199). 

HOLOTHUROIDEA.  Worm-like,  with  tentacles  around  mouth 
(201). 

ANNELIDA 

Bilateral,  segmented  worms  without  jointed  legs. 

POLYCH.3STA.  Annelida  possessing  parapodia  on  one  or  more 
segments,  and  with  many  bristles  on  parapodia.  ERRANTIA,  free- 
swimming  Polychaeta:  Autolytus  (147),  Lepidonotus  (147),  Xe- 
reis  (145),  Euglycera  (147).  SEDKNTARIA,  Polychaeta  which  live  in 
tubes  composed  of  mud,  sand,  or  lime:  Cirratulus  (149),  Amphi- 
trite  (150),  Polycirrus  (150),  Cistenides  (151),  Clymenella  (150), 
Serpula  (151). 

OLIGOCH^ETA.  Annelida  without  parapodia  and  with  few  setae ; 
living  in  fresh  water  or  in  the  ground.  LIMICOL^:,  aquatic  :  Nais 
(137);  Dero  (137);  Tubifex  (136).  TERRICOL*:,  earth-inhabiting: 
Allolobophora,  Lumbricus  (133). 

GEPHYREA.  Annelida  having  sessile  habits  and  consequently 
without  external  segmentation  in  the  adult,  setae  sometimes  present. 
Phascolosoma  (139),  Echiurus  (139). 

HIRUDINEA.  Annelida  with  short  rings  or  none  at  all  and  with 
a  ventral  sucker ;  "bloodsuckers."  Clepsine  (141)  ;  Nephelis  (140). 

ARTHROPODA 

Symmetrical,  segmented  animals,  with  jointed  appendages. 
CRUSTACEA.     Typically,  aquatic   and   gill-bearing  Arthropoda. 
Two  pairs  of  antennae,  except  in  Gigantostraca. 


SYNOPSIS   OF  THE  ANIMAL   KINGDOM  387 

[ENTOMOSTRACA].  Crustacea  with  varied  number  of  pairs 
of  appendages ;  usually  of  small  size.  BRANCHIOPODA,  mandibles 
without  palps,  numerous  legs  (127).  TRILOBITA,  fossil  (130).  CLA- 
DOCERA,  mandibles  palpless,  few  legs  (126).  OSTRACODA,  palp  on 
mandible,  only  two  pairs  of  legs  (127).  COPEPODA,  elongated  Crusta- 
cea, with  only  one  pair  of  maxillae ;  females  with  external  ovisacs 
(127).  CIRRIPEDIA,  attached  Crustacea  (barnacles,  129). 

[MALACOSTRACA].  Crustacea  with  nineteen  pairs  of  appen- 
dages. AMPHIPODA  (112).  ISOPODA  (112).  CUMACEA  (112).  STO- 
MATOPODA  (111).  PODOPTHALMATA  :  [MACRURA],  large-tailed 
Podopthalmata :  Candida  (104);  Astacidce  (97);  Thalassinidce  (105)  ; 
Paguridce  (105)  ;  Hippidce  (107).  [BRACHYURA],  crabs  :  Oxyrliyncha 
(107)  ;  Cyclometopa  (108)  ;  Catometopa  (110). 

[GIGANTOSTRACA].  Crustacea  with  five  pairs  of  appen- 
dages on  cephalo-thorax,  abdomen  without  feet ;  body  ends  in  a  long 
telson,  Limulus  (114). 

ARACHNOIDEA.  Air-breathing  Arthropoda  without  antennae. 
ACARINA,  mites  (95).  PYCNOGONIDA,  sea-spiders  (95).  ARENEINA, 
spiders:  Saltigradce  (90);  Citigradce  (89);  Laterigmdas  (89);  Tulri- 
telarice  (88)  ;  Retitelarice  (87)  ;  Orbitelarice  (86)  ;  Territelarice  (85). 
PHALANGINA,  harvest-men  (93).  ARTHROG ASTRA,  scorpions  (92). 

TRACHEATA.  Air-breathing  Arthropoda,  with  one  pair  of 
antennae. 

[MYRIAPODAJ.  Tracheata  with  distinct  head  and  abdomen, 
all  the  segments  of  the  abdomen  bearing  appendages.  CHILOPODA, 
centipedes  :  Scutigeridce  (75)  ;  Lithobiidre  (75)  ;  Scolopendridce  (76) ; 
Geophilidce  (76).  DIPLOPODA,  millipedes :  Julidce  (76)  ;  Polydesmidce 
(77).  SYMPHYLA:  Scolopendrella  (78),  Pauropus  (77). 

[HEXAPODA].  Tracheata  with  only  three  pairs  of  legs,  con- 
fined to  thorax.  ORTHOPTERA,  Hexapoda  with  two  pairs  of  wings, 
masticating  mouth-parts,  incomplete  metamorphosis :  Forficulida>  (9)  ; 
Blattidce  (8);  Mantidce  (8);  Phasmidce  (7);  Acridldce  (2);  Locmtidce 
(5);  Grillidce,  (4).  NEUROPTERA,  Hexapoda  with  two  pairs  of  net- 
veined  wings;  biting  mouth-parts,  metamorphosis  complete  or  in- 
complete: Odonata  (9);  Ephemeridce  (10)  ;  Termitidce  (11);  Sialidce. 
Corydalis  (12).  HEMIPTERA,  Hexapoda  with  two  pairs  of  wings  or 
none,  sucking  and  piercing  mouth-parts,  incomplete  metamorphosis. 
[HETEROPTERA],  upper  wings  leathery:  Reduviidce  (12).  [Ho.MOp- 


388  ZOOLOGY 

TERA],  wings  alike:  Cicada  (14)  ;  [here,  also,  plant  lice  and  animal 
lice].  DIPTERA  :  Hexapoda  with  (typically)  one  pair  wings;  pierc- 
ing and  sucking  mouth-parts ;  complete  metamorphosis.  [APHANIP- 
TERA],  fleas  (71).  [PUPIPARA]  :  Hippoboscidce  (71).  [BRACHYCERA], 
true  flies :  Muscidce  (62)  ;  (EstridcB  (65)  ;  Syrphidce  (66)  ;  Asilidce  (66)  ; 
Tabanidce  (66);  Simuliidce  (67).  [NEMATOCERA],  gnats:  Ceci- 
domyidce  (67)  ;  Culicidce  (69)  ;  Tipulidce  (70).  COLEOPTERA,  Hexa- 
poda whose  fore  wings  are  modified  into  wing  covers ;  hind  wings 
folded  when  not  in  use :  Coccinellidce  (55) ;  Chrysomelidce  (54)  ; 
Cerambycidce  (54)  ;  Curculionidce  (53)  ;  Scolytidce  (53)  ;  Tenebrionidce 
(52) ;  Lampyridce  (51)  ;  Elateridce  (51)  ;  Buprestidce  (51) ;  Lamelli- 
cornia  (49)  ;  Lucanidce  (49)  ;  Dermestidce  (49)  ;  Silphidce  (48)  ;  Stap'hy- 
linidce  (47);  Hydropliilidce  (47);  Gyrinidce  (46);  Dytiscidce  (46); 
Carabidce  (45) ;  Cicindelidce  (45).  LEPIDOPTERA,  Hexapoda  with 
two  pairs  of  scale-covered  wings,  sucking  mouth-parts,  complete  meta- 
morphosis :  Tineidce  (29)  ;  Tortricidce  (29)  ;  Pyralidce  (29);  Geometridce 
(28);  Noctuidce  (19,28);  Bombycidce  (26);  Arctiidce  (24);  Xylotropi- 
dce  (23);  Sphingidce  (22);  Papilionidce  (21).  HYMENOPTERA,  Hexa- 
poda with  two  pairs  of  membranous  wings ;  biting  and  licking  mouth- 
parts  ;  complete  metamorphosis:  [PHYTOPHAGA],  plant-eating  (38). 
[ENTOMOPHAG A]  insect  parasites  (38).  [ACULEATA]  stinging:  For- 
micidce  (34)  ;  Fossoria  (34) ;  Vespidce  (33)  ;  Apidce  (31). 

CHORDATA 

Animals  which  possess,  at  some  time  of  life,  throat  slits  and  a  dor- 
sal supporting  rod  or  chorda. 

[HEMICHORDA] 

Animals  of  worm-like  form,  showing  gill-slits  like  fishes.     Balano- 
glossus  (251). 

[TUNICATA] 

Chordata  which  are  either  attached  or  form  colonies  or  both  (251). 

[VERTEBRATA-ACRANIA] 

Free-living  fish-like  Chordata,  but  without  skull,  paired   fins,  or 
heart,  and  with  colorless  blood.     Amphioxus  (251). 


SYNOPSIS  OF  THE  ANIMAL  KINGDOM  389 


[VERTEBRATA-CRANIATA] 

Free-living  Chordata,  with  skull  and  complex  brain,  and  red  blood. 

CYCLOSTOMI.  Eel-like  vertebrates  without  lower  jaw,  and  living 
a  parasitic  life  (245). 

PISCES.  Aquatic  vertebrates  with  gills,  without  lungs,  and  with 
paired  fins  instead  of  legs.  SELACHII,  skeleton  cartilaginous,  no 
operculum,  spiral  valve  (246).  GANOIDEI,  skeleton  either  cartilagi- 
nous or  bony,  spiral  valve  and  operculum  present :  sturgeons  (247) ; 
spoon-bill  (247);  garpike  (248)  ;  bowfin  (248).  TELEOSTEI,  skeleton 
bony,  no  spiral  valve.  [ACANTHOPTERI],  dorsal,  anal,  and  ventral  fins 
with  spines,  pharyngeal  bones  distinct :  perches  (235)  ;  darters  (234)  ; 
sunfishes  (235)  ;  toadfishes  (236) ;  sculpins  (236)  ;  silversides  (236) ; 
sticklebacks  (238).  [PHARYNGOGNATHI]  fins  with  spines,  pharyngeal 
bones  united.  [ANACANTHINI],  fins  without  spines,  ventral  fins  far 
forward  :  codfishes  (239)  ;  flatfishes  (240).  [PHYSOSTOMI],  fins  with- 
out spines,  ventral  fin  placed  far  backward :  smelts  (230)  ;  trouts  (233)  ; 
whitefishes  (234);  catfishes  (239);  suckers  (241);  minnows  (242); 
pikes  (242)  ;  shads  (243);  eels  (244).  [PLECTOGNATHI],  intermaxil- 
laries  and  maxillaries  united.  [LOPHOBRANCHII],  body  covered  with 
bony  plates  :  pipefishes  (244). 

AMPHIBIA  (=  Batrachia).  Vertebrata  having  no  lateral  fins  (but 
instead,  legs)  ;  functional  external  gills  during  a  part  of  their  life. 
URODELA.  Amphibia  which  retain  the  tail  permanently:  Sirenidce 
(255);  Proteidce  (257);  Amphiumidce  (257);  Cryptobranchidce  (257); 
Amblystomidce  (257);  Plethodontidce  (259);  Desmognathidce  (259). 
Pleurodelidce  (254).  ANURA,  Amphibia  which  lose  the  tail  in  the 
adult  stage :  Pipidce  (263) ;  Hylidce  (263)  ;  Bufonidce  (265)  ;  Ranidce 
(265).  GYMNOPHIONA,  Amphibia  which  have  no  limbs  nor  tails; 
body  worm-like. 

REPTILIA.  Vertebrata  which  breathe  exclusively  by  lungs  and 
whose  skin  contains  horny  epidermal  scales  or  bony  plates.  CHELONIA, 
trunk  enclosed  in  a  bony  case :  Chelonidce  (274)  ;  Trionychidce  (274)  ; 
Testudinidce  (275).  SAURIA,  shoulder-girdle  and  sternum  present, 
usually  with  eyelids  :  Chamceleonidce  (272)  ;  lyuanidce  (268)  ;  Varanidce 
(269);  Lacertidce  (270);  Helodermidce  (270);  Anguidce  (271).  OPHI- 
DIA,  footless  scaled  reptiles  with  no  shoulder-girdle,  sternum,  nor 


890  ZOOLOGY 

movable  eyelids :  Colubridce  (276) ;  Elapidce  (277)  ;  Crotalidce  (277). 
CRQCODILINA,  large  reptiles,  with  longitudinal  vent  (279). 

AVES.  Feathered  Vertebrates.  CUKSORES,  Aves  with  keelless 
sternum  (307).  NATATORES,  swimming  birds  (305).  GRALLATORKS, 
wading  birds  (305).  GALLINACEI,  large  ground  birds  with  strong, 
perching  feet  and  flat  nails  (304).  COLUMBINE,  short  cloven  feet  and 
compressed  nails  (303).  SCANSORES,  birds  with  powerful  beak  and 
feet  adapted  for  climbing  (299).  CYPSELOMOPH^:,  cereless  birds,  with 
scaleless  metatarsus  (301).  PASSERES,  birds  whose  metatarsus  is 
covered  with  laminae  or  scales,  usually  with  singing  apparatus  :  Tyran- 
nidce  (295)  ;  Alaudidce  (295)  ;  Corvidce  (294)  ;  Icteridce  (293)  ;  Fringil- 
/iW«(284);  Tanagridce  (292);  Hirudinidce  (292);  Ampelidce  (291); 
Laniidce  (289) ;  Vireonidce  (288) ;  Mniotilidce  (287) ;  Troglodytidce 
(287);  Certhiidce  (286);  Paridce  (286);  Sylviidce  (285);  Turdidce 
(285).  RAPTORES,  birds  with  cere,  hooked  bill,  and  strong,  hooked 
claws  (298).  PSITTACI,  birds  with  cere,  high,  hooked  beak,  and 
fleshy  tongue  (parrots,  297). 

MAMMALIA.  Vertebrates  which  nourish  the  young  by  means  of 
milk,  and  are  usually  covered  with  hair.  MONOTREMATA,  oviparous 
mammals  (321).  MARSUPALIA,  provided  with  a  marsupium  (322). 
EDENTATA,  teeth  either  absent,  rudimentary,  or  without  enamel  (323). 
CETACEA,  marine  hairless  mammals,  hind  limbs  absent  (324).  UNGU- 
LATA,  hoofed  mammals :  even-toed  ungulates  (326) ;  odd-toed  ungu- 
lates (327);  elephants  (327).  RODENTIA,  canines  absent,  incisors 
grow  continuously  through  life  (320).  CARNIVORA,  canines  large 
(328).  INSECTIVORA,  small,  terrestrial,  carnivorous  mammals,  with 
small  canines  (327).  CHEIROPTERA,  mammals  with  flying  membrane 
between  elongated  digits  (329).  PRIMATES,  with  hands  (329). 


GLOSSARY 


abdomen,  in  Arthropoda,  the  hinder- 
most  of  the  three  divisions  of  the 
body,  59. 

aboral,  the  side  of  the  body  opposite 
to  the  mouth,  193. 

alveolus,  a  depression,  e.g.  the  socket 
of  a  tooth,  280. 

angulated,  forming  an  angle  or  sharp 
corner ;  opposed  to  rounded,  249. 

antenna,  horn  or  feeler,  one  of  the 
anterior  tactile  appendages  of  Ar- 
thropoda and  Mollusca,  4,  4(3. 

anterior,  situated  at  the  front  end  of 
the  body. 

anus,  the  posterior  opening  of  the  food 
canal. 

aorta,  the  main  blood-vessel  coming 
from  the  heart. 

articular,  relating  to  a  joint;  the 
hinge  bone  of  the  lower  jaw  of 
fishes,  232. 

atripore,  the  external  opening  of  the 
atrium,  249. 

atrium,  or  vestibule,  a  chamber  placed 
either  in  front  of  the  mouth  or,  in 
Chordata,  around  the  gill-slits. 

auditory  clubs,  club-shaped  sense  or- 
gans on  the  margin  of  the  bell  of 
jelly-fishes,  221. 

basihyal,  a  bone  found  in  fishes,  form- 
ing the  base  of  the  U-shaped  arch 
which  supports  the  tongue,  232. 

bifid,  two-parted. 

bivalve,  having  two  valves  or  shells, 
131,  178. 


blastula,  a  stage  in  the  early  develop- 
ment of  the  egg  when  it  forms  a 
hollow  sphere,  193. 

branchial,  relating  to  the  gills. 

branchiate,  bearing  gills,  131. 

branchiostegal  rays,  the  bony  rays 
supporting  the  membrane  below  the 
bones  of  the  operculum  in  fishes, 
232. 

buccal,  pertaining  to  the  mouth  cavity 
or  cheeks,  59,  143. 

byssus,  a  tuft  of  tough  threads  spun 
from  the  foot  of  bivalves  and  used 
for  attachment  to  foreign  bodies, 
180. 

calcareous,  consisting  of  a  calcium  or 
lime  compound. 

calcified,  rendered  calcareous  by  depo- 
sition of  salts  of  lime. 

callus,  a  soft  substance  secreted  over 
a  harder  bony  material,  175. 

calyx,  cup. 

cambered,  concave  on  the  under  side, 
42. 

canine,  or  canine  tooth,  the  pointed 
tooth  situated  immediately  behind 
the  front  cutting  teeth,  331. 

capsule,  a  little  sac  containing  a  fluid. 

carapace,  the  thick  shell  or  skin  cov- 
ering the  back  of  Crustacea  or  Che- 
Ionia,  103,  280. 

cardinal,  belonging  to  the  hinge,  as 
the  teeth  of  lamellibranch  shells, 
188. 

carnivorous,  flesh-eating. 


391 


392 


ZOOLOGY 


cephalothorax,  united  head  and  thorax. 
cere,  a  waxy  sheath  at  the  base  of  the 

bill  of  certain  birds,  315. 
chelicera,  the  first  pair  of  mouth  ap- 
pendages in  the  Arachnida,  80. 
cilia,  microscopic,  vibratile  processes 

of  certain  cells. 
cirrus,  a  filamentous  appendage  of  the 

parapodia  of  Annelida,  159. 
cleavage,  the  multiplication  of  cells  at 

the  beginning  of  the  development  of 

the  egg,  193,  336. 
clitellum,  a  thickened  glandular  ring 

sometimes  found  in  the  earthworm. 
coxa,  that  joint  of  an  Arthropod  leg 

which  is  nearest  the  trunk,  59. 
culmen,  the  upper  ridge  of  a  bird's  bill. 
cuticula,  the  tough  secreted  "skin" 

covering  arthropods,  hydroids,  and 

other  animals. 

dentary,  a  bone  of  the  lower  jaw  of 
fishes  which  carries  the  teeth. 

dextral,  right,  applied  to  right-handed 
shells,  166. 

diaphragm,  a  dividing  membrane,  119. 

elytron,  the  horny  upper  wings  of 
beetles,  59. 

enamel,  the  hard  covering  of  teeth 
and  some  fish  scales,  248. 

encyst,  the  act  of  secreting  a  cyst  or 
vesicle,  227. 

enteric,  pertaining  to  the  enteron  or 
food  canal. 

epidermis,  the  outermost  skin  of  ver- 
tebrates; also  a  superficial  horny 
secretion  over  the  shells  of  mol- 
lusks,  175. 

epimeron,  a  lateral  piece  behind  the 
episternum  of  insects,  59. 

epiotic,  one  of  the  bones  surrounding 
the  inner  ear  in  the  lower  verte- 
brates, 232. 


episternum,  a  piece  just  lateral  to  the 
sternum  in  the  thorax  of  insects,  59. 

epistome,  in  beetles,  a  piece  above  the 
mouth,  59. 

facetted,  composed  of  numerous  small 
eyes,  making  up  a  compound  eye,  78. 

femur,  thigh  of  insects,  59. 

fertilization,  the  union  of  two  germ- 
cells,  335. 

flagellum,  a  microscopic,  lash-like, 
vibrating  thread  of  certain  Infuso- 
ria, 226. 

foliaceous,  leaf-like. 

frontal,  applied  to  a  bone  of  the  skull 
lying  between  the  orbits,  232. 

gastrolith,  a  calcareous  nodule  occur- 
ring in  the  stomach  of  the  higher 
Crustacea,  103. 

gastrula,  a  stage  in  development  of 
the  egg  just  after  the  digestive  cav- 
ity has  been  formed,  193. 

gastrulation,  the  process  of  forming 
the  gastrula,  336. 

gonad,  a  germ-producing  gland,  221. 

gonophore,  a  sexual  zooid,  generally 
reduced  to  an  exclusively  reproduc- 
tive function,  212. 

gula,  the  throat  plate  on  under  part  of 
the  head  of^ insects,  59. 

hsemal,  relating  to  the  blood  system. 
hirsute,  hairy,  shaggy,  42. 
hydranth,  the  "  heads  "  or  zooids  of 

a  hydroid  stock,  210. 
hyomandibular,    a    bone   which,    in 

fishes,  connects  the  lower  jaw  with 

the  skull,  232. 

imago,  the  adult  of  an  insect. 
intermaxillary,  the  same  as  premaxil- 
lary. 


GLOSSARY 


393 


inter  op  er  cular ,  the  posterio-inferior 
opercular  bone  of  fishes,  232. 

jugal,  the  cheek-bone,  232. 

keel,  a  ridge  on  the  breast-bone  of 
birds  for  attachment  of  flying  mus- 
cles, 314. 

labial,  pertaining  to  the  labium. 
labium,  the  under  lip  of  insects,  59. 
labrum,  the  upper  lip  of  insects,  59. 
lamella,  a  leaf  or  plate,  58. 
lamina,  a  thin  plate. 
lancet  cell,  a  lancet-shaped  cell  on  the 

hinder  margin  of  the  fore  wing  of 

Phytophaga,  43. 
larva,  an  immature  but  active  stage  of 

development,  10. 

ligula,  the  front  edge  of  the  labium,  59. 
liver  area,  in  crabs,  the  anterio-lateral 

area  of  the  carapace  in  front  of  the 

gill  region,  123. 

lumen,  the  central  space  of  a  tube. 
lunule,  a  crescentic  or  heart-shaped 

area  in  front  of  the  beak  of  some 

bivalve  shells,  190. 

madreporic  plate,  in  echinoderms,  a 

perforated  plate  admitting  water  to 

the  system  of  water  tubes,  204. 
mandible,    in    arthropods,   the    most 

anterior    of   mouth    parts,    59;    in 

vertebrates,  the  bone  of  the  lower 

jaw. 
mantle,  the  fold  of  the  skin  of  a  mol- 

lusk,  or  cirriped,  which  secretes  the 

shell,  160. 
manubrium,  in  jelly-fishes,  the  mouth 

stalk,  corresponding  in  position  to 

the  clapper  of  a  bell,  211. 
marsupium,  a  pouch,  in  Marsupalia, 

on    the  ventral  side  of   the  body, 

331. 


maxilla,  in  Arthropoda,  one  of  the 
mouth  parts  immediately  following 
the  mandible,  59 ;  in  vertebrates,  a 
tooth-bearing  bone  of  the  upper  jaw. 

maxillary,  relating  to  the  maxilla. 

maxilliped,  one  of  the  foot-like  mouth 
parts  which  in  arthropods  follow 
the  maxillae. 

mentum,  the  front  plate  of  the  labium 
in  insects,  59. 

mesopterygoid,  one  of  the  bones  form- 
ing the  base  of  the  skull  in  bony 
fishes,  232. 

mesothorax,  the  middle  segment  of  the 
thorax,  59. 

metamerism,  the  fundamental  repeti- 
tion of  parts  of  the  body  along  the 
longitudinal  axis,  as  in  earthworms 
139. 

metapleure,  in  Amphioxus,  a  latero- 
ventral  fin,  249. 

metapterygoid,  one  of  the  bones  form- 
ing the  base  of  the  skull  in  bony 
fishes  and  lying  behind  the  mesop- 
terygoid, 232. 

metasternum,  the  ventral  plate  of  the 
last  thoracic  segment  of  insects,  59. 

metatarsus,  in  birds,  the  foot  proper, 
315. 

metathorax,  in  insects,  the  third  or 
last  segment  of  the  thorax,  59. 

morula,  an  early  stage  of  egg  develop- 
ment when  the  germ  consists  of  a 
nearly  solid  mass  of  cells,  336. 

moult,  to  change  the  skin,  as  in  in- 
sects. 

myocomma,  the  thin  layer  separating 
two  muscle  plates  in  vertebrates,  246. 

myomere,  a  muscle  plate,  246. 

nasal,  belonging  to  or  forming  the 

nose,  as  nasal  bones. 
neural,    pertaining   to   the    nervous 

system. 


394 


ZOOLOGY 


neural  groove,  the  groove  which  marks 
in  the  vertebrate  embryo  the  devel- 
oping central  nervous  system,  261. 

nodulous,  covered  with  nodules  or 
little  lumps,  175. 

notochord,  the  axial  supporting  rod  of 
chordates,  249. 

(jesophayus,  the  gullet,  the  part  of  the 

food  canal  leading  to  the  stomach. 
operculum,  in  gastropods,  the  horny 

plate  which  closes  the  aperture ;  in 

fishes,  the  gill-cover,  232. 
oviduct,  the  duct  which  carries  eggs 

from  the  body,  120. 
oviposit,  to  lay  eggs,  as  in  insects,  53. 

palatine,  of  the  palate  or  roof  of  the 
mouth ;  name  of  a  pair  of  bones 
forming  the  palate,  232. 

pallial  line,  streak  formed  in  a  bivalve 
shell  by  the  margin  of  the  attached 
mantle. 

pallial  sinus,  an  incurving  of  the  pal- 
lial line  to  receive  the  siphon  in  cer- 
tain lamellibranchs. 

palp,  a  secondary  sensory  outgrowth 
of  a  mouth  part  of  an  insect,  59. 

paraglossse,  a  pair  of  small  appendages 
of  the  under  lip  of  insects,  59. 

parapodia,  the  paddling  feet  of  poly- 
chsetes,  147. 

parasitic,  living  on  the  nutritive  juices 
elaborated  by  another  organism. 

parasphenoid,  a  bone  occupying  the 
base  of  the  skull,  267. 

parietal,  bones  of  the  middle  upper 
part  of  the  brain  case,  232. 

pectinate,  comb-like. 

pectoral,  of  the  chest ;  the  chest  limbs 
of  fishes,  246. 

pedicellariee,  minute  forceps-like  or- 
gans found  on  some  echinoderms, 
194. 


pelvic  Jin,  or  ventral  fin,  the  hinder 

paired  appendages  of  fishes,  246. 
penultimate,  next  to  the  last. 
percoid,  like  a  perch. 
perisarc,  the  outer  tough  skin  of  hy- 

droids,  211. 
pharynyeal,  relating  to  the  pharynx 

or  throat,  252. 

polyp,  the  sessile  form  of  coelenterates. 
posterior,  situated  behind. 
premaxilla,  the  most  anterior  tooth- 
bearing  bone  of  the  upper  jaw  of 

fishes,  232. 
preopercular,  the  most  anterior  of  the 

bones  of   the  operculum  of   fishes, 

232. 
primaries,  the  large  feathers  on  the 

distal  joint  of  a  bird's  wing,  315. 
proboscis,  in  insects,  a  sucking  tube 

connecting  with  the  mouth,  61. 
prosternum,  the  most  anterior  of  the 

ventral  platesMn  the  thorax  of  in- 
sects, 59. 
prostomium,  in  worms,  a  lobe  of  the 

body  projecting  above  and  in  front 

of  the  mouth. 
prothorax,  the  most  anterior  of  the 

segments  of  the  thorax  of  insects, 

59. 
pseudobranch,  in  fishes,  a  rudimentary 

gill  in  front  of  the  first  throat  slit, 

231. 
pseudopodia,  retractile   processes   in 

Protozoa. 
pterotic,  one  of  the  ear  bones  of  fishes, 

232. 
pteryyoid,  a  bone  of  the  base  of  the 

cranium,  232. 
pupa,  a  stage  in  insect  development 

preceding  the  imago,  11. 

quadrate,  a  bone  lying  between  the 
skull  and  the  hinge  of  the  lower  jaw 
in  fishes,  232. 


GLOSSARY 


395 


radii,  lines  proceeding  from  a  common 

centre  like  the  spokes  of  a  wheel, 

86. 
ramus,  a  branch  or  projecting  process, 

131. 
rictus,  the  corners  of  the  mouth  in 

birds,  315. 
rostrum,  beak,  the  frontal  process  of 

crustaceans. 

scansorial,  capable  of  climbing,  315. 

scutellate,  composed  of  plates,  315. 

scutellum,  the  third  of  the  four  pieces 
composing  the  upper  part  of  a  tho- 
racic segment  of  an  insect,  59. 

septa,  the  radial  calcareous  plates  of 
a  coral,  215. 

sinistral,  left. 

siphon,  the  drawn-out  edges  of  the 
mantle  folds  of  lamellibrauchs,  183; 
the  strand  penetrating  the  chambers 
of  the  Nautilus  shell,  also  called 
siplmncle,  173. 

spatulate,  shaped  like  a  spatula,  or  a 
paddle. 

sphenotic,  one  of  the  bones  forming 
the  ear  capsule  of  fishes,  232. 

spinnerets,  the  tubercles  through  open- 
ings in  which  the  spider  thread  is 
spun,  84. 

spiracle,  one  of  the  openings  to  the 
air-tubes  of  insects,  59. 

spurious,  not  genuine. 

squame,  a  scale  in  decapods  attached 
to  the  antenna,  124. 

sternum,  in  vertebrates,  the  breast- 
bone, 280;  in  insects,  the  ventral 
part  of  a  somite,  59. 

stiamata,  spiracles'. 

stock,  colony,  207, 


stolon,  a   runner  from  which   zooids 

bud,  220. 
subopercular,  the  lowermost  bone  of 

the  operculum  in  fishes,  232. 
suborbital,  a    bone    in    fishes,    lying 

below  the  eye,  232. 
supraethmeoid,  a  bone  of  the  nose  in 

fishes,  232. 
supraoccipital,   a    bone   forming    the 

upper  part  of  the  back  of  the  head. 
suture,  a  seam  or  structural  line,  70. 
syinplectic,  a  bone  uniting  the  quad- 
rate to  the  bones   suspending   the 

lower  jaw,  232. 

tarsus,  the  jointed  foot  of  an  arthro- 
pod leg,  59. 

telvon,  the  tail-piece  of  a  crustacean, 
116. 

tentacle,  a  projecting  tactile  organ. 

thoracic,  pertaining  to  the  thorax  or 
chest. 

tibia,  the  joint  of  an  insect's  leg  next 
above  the  tarsus,  59. 

trachea,  one  of  the  respiratory  tubes 
of  insects,  64. 

trochanter,  a  joint  of  the  insect  leg 
lying  distal  to  the  coxa,  59. 

umbilicus,  a  depression  in  the  centre 
of  the  base  of  many  spiral  sbells, 
175. 

umbones,  a  protuberance  just  above 
the  hinge  of  a  bivalve  shell,  188. 

velum,  a  circular  membrane  extend- 
ing like  a  shelf  from  the  margin  of 
the  jelly-fish  bell,  211. 

viviparous,  giving  birth  to  well-de- 
veloped progeny,  331. 


INDEX 


Aardvark,  323. 

Abnormalities,    lobster,   119;    plana- 

rians,  155;  starfish,  196. 
Acanthocottus,  236. 
Acanthopteri,  252. 
Acarina,  95. 
Acartia,  128. 
Accipiter,  298. 
Acineta,  225. 
Acipenser,  247. 
Acmaea,  170., 
Acmaeidae,  177. 
Acrania,  252. 
Acrididje,  1,  15. 
Actitis,  306. 
Adalia,  56. 
Adeorbidse,  175. 
Admiral,  21. 
^schna,  10. 
Agalena,  90. 
Agricultural  ant,  37. 
Alaudidas,  259,  317. 
Alligator,  279. 
Allolobophora,  114. 
Alosa,  243. 

Amblystoma,  257,  335. 
Amblystomidse,  257,  267. 
Ameiurus,  240. 
American  crossbill,  284. 
Amia,  248. 
Ammonites,  173.  . 
Amoiba,  227,  229. 
Ampelidae,  291,  317. 
Ampelis,  291. 
Amphibia,  254;  distribution  of,  255; 

metamorphosis  of,  260. 
Amphioxus,  249,  252. 
Amphipoda,  112. 
Amphitrite,  149,  150, 159. 


Amphiuma,  198. 

Amphiumidse,  257,  266. 

Amphiura,  198.  «. 

Anacanthini,  253. 

Anatis,  56. 

Ancestry  of  vertebrates,  248. 

Angle  wings,  21. 

Anguidse,  271. 

Annelida,  136. 

Anodonta,  191 ;  embryo  of,  180 ;  food 
of,  178 ;  habitat  of,  178. 

Anolis,  268. 

Anomiidae,  191. 

Anthremis,  48. 

Ant-eater,  322. 

Antelopes,  326. 

Anthophagus,  47. 

Ants,  30,  34,  43;  army,  37;  colonies 
of,  35 ;  intelligence  of,  35 ;  language 
of,  36 ;  leaf-cutting,  37 ;  social  life  of, 


Anura,  255,  262,  266. 
Apes,  230. 

Aphaniptera,  61,  70. 
Aphids,  14. 
Aphrodite,  148. 
Aphroditidae,  159. 
Apidae,  31,  42. 
Aplysia,  164. 
Apteryx,  307,  308. 
Arachnoidea,  92. 
Arbacia,  200. 
Area,  184. 
Archaeopteryx,  314. 
Arched  crabs,  123. 
Archiaster,  195. 
Arcidae,  184. 
Arctiidae,  24,  41. 
Araneina,  80,  95. 
Argiope,    80-83,   86; 
397 


distribution  of, 


398 


ZOOLOGY 


83 ;  food  of,  82 ;  spinning  habits  of, 

82. 

Argonauta,  172. 
Arion,  162. 
Ark  shells,  162. 
Armadillo,  323. 
Army  ants,  37. 
Army  worm,  28. 
Arthrogaster,  92. 
Ascaris,  151. 
Asilidaa,  66. 
Asiphonata,  178. 
Asp,  277. 

Asparagus  beetle,  56. 
Assassin  bug,  12. 
Astacidse,  124. 
Astacus,  97-99,  113. 
Astartidae,  190. 

Asterias,  197 ;  distribution  of,  192, 197. 
Asteriodea,  197,  203. 
Astrangia,  216. 
Atoll,  217. 
Attus,  91. 

Auriculidae,  161,  166,  176. 
Autolytus,  147,  159. 
Aviculidae,  185. 
Axolotl,  258,  260. 

B 

Baboon,  330. 

Badger,  328. 

Balauinus,  53. 

Balanoglossus,  250,  251. 

Balanus,  129. 

Bald  eagle,  298. 

Baltimore  oriole,  293. 

Banded  horse-fly,  66. 

Bark-borer,  53. 

Barnacles,  102 ;  habits  of,  129. 

Barn-swallow,  292. 

Barrier  reef,  217. 

Bat,  329 ;  food  of,  329. 

Batrachia,  254. 

Batrachus,  236. 

Bears,  328. 

Beaver,  310. 

Beaver  parasite,  5(5. 

Bee-moth,  29. 

Bees,  30,  31,  42 ;  swarming,  32. 


Beetle,  44;  development  of,  44;  eco- 
nomic importance  of,  57;  food  of, 
56;  larval  habits  of,  45;  number 
of  species  of,  45. 

Bell-hydroid,  209. 

Belted  kingfisher,  300. 

Birds,  281;  economic  importance  of, 
311 ;  extinct,  313;  flight  of,  310;  pro- 
tection of,  312;  migration  of,  309; 
teeth  of,  314. 

Bird's-nest,  edible,  303. . 

Bittern,  305. 

Black-fly,  66. 

Black  lobster,  103. 

Black  moccasin ,  279. 

Black  snake,  276. 

Blattidae,  8,  H. 

Blister-beetle,  57,  61. 

Blow-fly,  61. 

Blue,  22. 

Bluebird,  285. 

Bluejay,  295. 

Boa,  276. 

Bobolink,  294. 

Boll-worm,  28. 

Bombus,  31. 

Bombycidae,  24,  42. 

Bombyx,  24. 

Bonasa,  304. 

Bony  fishes,  252. 

Bosminid*,  131.   . 

Bot-flies,  64,  72. 

Botryllus,  250. 

Bougainvillea,  211. 

Bowfin,  248. 

Box  tortoise,  275. 

Brachiopoda,.l27,  130. 

Brachycera,  61,  63.    -    . 

Brachyura,  107. 

Branchipus,  127,  130. 

Brittle-stars,  198. 

Brook  sucker,  241. 

Brown  creeper,  288. 

Bruchidae,  57. 

Bryozoa,141,  217. 

Buccinidae,  175. 

Buck-beetles,  54.- 

Budding,  217. 

Buffalo  gnat,  66,  72. 


INDEX 


399 


Bufo,  264. 

Bufonidae,  265. 

Bngula,  142. 

Bull-frog,  2(56. 

Bull-head,  241. 

Bullidfe,  174. 

Bumblebee,  31. 

Buprestidae,  51,  60. 

Buprestis,  51. 

Buthus,  93. 

Butterflies,  41 ;  broods  of,  17 ;  habits 

and  food  of,  16 ;  mimicry  of,  18-21 ; 

polymorphism    of,    17;    protective 

resemblance  of,  18-21. 


Cabbage  butterfly,  18. 

Callianassa,  105. 

Gallinectes,  109. 

Calosoma,  46. 

Calyptraeidae,  177. 

Cambaroides,  99. 

Cambarus,  99,  100,  113. 

Camels,  326. 

Campanularian  hydroids,  210. 

Campanularidae,  209,  221. 

Camponotus,  35. 

Canada  grouse,  304. 

Cancer,  114. 

Carabidje,  45-46,  60. 

Carchesium,  224;  food  of,  225. 

Cardiidae,  190. 

Cardinal  grosbeak,  285. 

Carididae,  124,  180. 

Carolina  paroquet,  297. 

Carnivora,  328,  331. 

Carpenter  ant,  35. 

Carrion-beetles,  48,  57,  60. 

Carrion-fly,  73. 

Case-bearers,  29. 

Cassowary,  307. 

Catfishes,  239,  253;-Tange  of,  239-240. 

Catocala,  19,  28. 

Catometopa,  123. 

Caudina,  201,  203. 

Caviare,  247. 

Cecidomyidae,  66,  68. 

Cedar-bird,  292. 

Cedar  waxwing,  291. 


Centipedes,  74. 

Centrurus,  93. 

Cephalopoda,  171. 

Ceratodus,  249. 

Cerambycidae,  54,  5(5,  61. 

Cerebratulus,  158. 

Cerithia,  288. 

Certhiidae,  286,  316. 

Cestoda,  386. 

Cetacea,  324,  331. 

Ceuthophilus,  6. 

Ceryle,  300. 

Chameleo,  272. 

Chameleon,  272. 

Cheetah,  328. 

Cheiroptera,  329,  331. 

Chelidon,  392. 

Chelonia,  273,  280. 

Chelonidte,  274. 

Chestnut-sided  warbler,  288. 

Chewink,  285. 

Chigger,  95. 

Chigoe,  71. 

Chilopoda,  74;  food  of,  74. 

Chimney-swift,  302 :  nest  of,  302. 

Chimpanzee,  330. 

Chipping-sparrow,  235. 

Chiton,  171. 

Chlorops,  72. 

Choloepus,  324. 

Chordata,  388. 

Chrysomelidae,  57,  61. 

Chrysops,  6(3. 

Cicada,  13;  pupal  case  of,  13. 

Cicindela,  45. 

Cicindelidae,  45. 

Ciliata,  229. 

Ciona,  250. 

Cirratulidae,  159. 

Cirratulus,  149,  159. 

Cirripedia,  131. 

Cistenides,  tube  of,  150. 

Citheronia,  25-26 ;  larvae  of,  25. 

Citig-radse,  89,  96. 

Civet-cats,  328. 

Cladocera,  127,  131. 

Clam,  178. 

Claws,  abnormal,  of  lobster,  120. 

Clepsine,  140-141. 


400 


ZOOLOGY 


Click-beetle,  61. 

Clisiocampa,  26,  27. 

Clothes-moths,  29-30. 

Clymenella,  150-159. 

Clypeaster,  201. 

Cnidaria,  205 ;  fresh-water,  207. 

Cobra,  277. 

Cobweb  spiders,  80. 

CoccinellidfE,  55,  61. 

Cockatoos,  297. 

Cockroaches,  8,  14. 

Codfishes,  253 ;  habitat  of,  239. 

Coslenterata,  form  of,  205. 

Colaptes,  301. 

Coleoptera,   key   to   families,  58-61; 

terminology,  59. 
Colonies,  of  ants,  35 ;  formation  of,  in 

Cnidaria,  217-218. 
Cojumba,  304. 
Columbellidae,  176. 
Cqlumbidae,  303. 
Columbinae,  314. 
Columbridae,  276. 
Condor,  298,  299. 

Congo  snake,  256 ;  habitat  of,  257. 
Con  urns,  297. 
Cooper's  hawk,  299. 
Cqpepoda,  127,  131. 
Copperhead,  279. 
Copris,  50. 

Coral  cup  of  Manicina,  216. 
Coral,    polyps,   215-216  ;     reefs,  216- 

217. 

Coregonus,  233. 
Cordylophora,  207-208. 
Corvidse,  294,  316. 
Cotton-worm,  28. 
Cow-bird,  293; 
Crab's  eyes,  104. 
Crab  spider,  89,  90,  96. 
Crane-flies,  68-69,  73. 
Cranes,  305. 
Craspedosomidae,  79. 
Crassatellidae,  190. 
Crayfish,  97, 122 ;  development  of,  117  ; 

edible,   113;  food  of,  98;   moulting 

of,  103,  subfamilies  of,  98-99. 
Creepers,  286. 
Crepidula,  169-170, 177. 


Cribrella,  196-198. 

Crickets,  4-5,  15. 

Cricket-grasshopper,  6. 

Crinoidea,  203. 

Crocodile,  279. 

Crocodilina,  279-280. 

Crossbills,  285. 

Crotalidae,  277-278. 

Croton  bug,  8. 

Crow,  294. 

Crow-blackbird,  293. 

Crustacea,  97,  104,  125. 

Cryptobranchidae,  257,  266. 

Cryptobranchus,  258. 

Ctenophora,  219-220. 

Cuckoos,  299 ;  laying  habit  of,  300. 

Culex,  68. 

Culicidse,  68. 

Cumacea,  122. 

Curculionidae,  53,  61. 

Cursores,  306,  315. 

Cuttlefishes,  172. 

Cyanocitta,  295. 

Cycladidae,  180,  191. 

Cyclas,  191 ;  habitat  of,  180 ;  distribu- 
tion of,  180-181. 

Cyclometopa,  123. 

Cyclostomi,  252,  habits  of,  245  ;  para- 
sitic on  fishes,  245-246. 

Cyclops,  127-128. 

Cyllene,  54-55. 

Cypselomorphae,  301,  315. 


D 

Daddy-long-legs,  93. 

Daphnia,  97,  125;  food  of,  126;  effect 

of  temperature  on,  127. 
Daphnidae,  131. 
Darcus,  49. 

Darters,  234,  252  ;  habitat  of,  234. 
Decapoda,   economic    importance   of, 

111 ;  eyestalks  of,  121. 
Deer,  326. 

Degenerate  flies,  70. 
Dendroctonus,  53. 
Dermestidae,  48,  49,  61. 
Dero,  137,  144. 
Desmognathidae,  259,  267. 


INDEX 


401 


Desmognathus,  color  of,  259;  habitat 
of,  2GO. 

Development,  of  beetle,  44;  crayfish 

,  117  ;  edentates,  333 ;  effect  of  heat 
on,  333;  effect  of  light  on,  333;  of 
egg,  115:  frog's  egg,  332;  fly,  62; 
general  laws  of,  335  ;  grasshopper, 
3-4 ;  lobster,  115-117 ;  Spelerpes,  261- 
262;  starfish,  193-194;  Urodela,261. 

Diapheromera,  7. 

Didelphys,  323. 

Diemyctylus,  267;  food  of,  254;  hab- 
itat of,  254 ;  life  history  of,  254-255. 

Digger  wasp,  34,  43. 

Diplocardia,  143. 

Diplopoda,  74. 

Dipnoi,  248,  252. 

Diptera,  61,  63,  72;  injurious  to  man, 
71;  scavengers,  72;  short-horned, 
63;  source  of  disease,  71. 

Discontinuous  genera,  99-100. 

Distomum,  155. 

Divers,  60,  306. 

Division  of  labor  in  Cnidaria,  219; 
physiological,  120. 

Dodo,  extermination  of,  314. 

Dogs,  328. 

Dogfish,  246. 

Dolphins,  324. 

Doryphora,  55. 

Downy  woodpecker,  301. 

Dragon-fly,  9-10. 

Duckbill,  322. 

Duck-bill  catfish,  247. 

Dytiscidae,  46,  56,  60. 

Dytiscus,  47,  138. 

E 

Eagles,  298. 
Earwigs,  9. 
Earthworm,  132-134;  economics  of, 

135;    food  of,  134;   habits  of,  132; 

regeneration  of,  134;  relationships 

of,  132 ;  resistance  of,  134. 
Echidna,  322. 
Echinarachnius,  201. 
Echinoidea,  322, 
Echinoids,  204. 
Echiurus,  139. 


Economic  importance,  of  beetles,  57; 
birds,  311;  decapods,  111;  earth- 
worms, 135;  parasitic  worms,  158; 
protozoa,  228;  slugs,  162;  starfish, 
193;  smelt,  230. 

Ectopistes,  304. 

Ectoprocta,  143. 

Edentata,  323,  331. 

Edentates,  discontinuity  of,  323. 

Edible,  birds'   nests,  303;    Carididse, 

\114;  crabs,  108-109,  113;  crayfish, 
113 ;  lobsters,  113. 

Eels,  253;  description,  distribution, 
reproduction,  244. 

Egg,  fertilization,  336 ;  masses  of  tent 
caterpillar,  26;  nauplius,  115. 

Egrets,  extermination  of,  305. 

Elapida3,  277. 

Elaps,  277. 

Elateridse,  51,  61. 

Elephants,  327. 

Endoprocta,  143. 

Enemies  of  lobster,  102. 

English  sparrow,  281;  food  of,  282; 
spread  of,  in  America,  281-282. 

Engraver  beetles,  61. 

En  sis,  182. 

Entomophaga,  43. 

Entomostraca,  97, 125. 

Eolis,  171. 

Ephemeridae,  10. 

Epiera,  80 ;  web,  87. 

Erycinidse,  190. 

Euglena,  225-226,  229. 

Euglycera,  146,  159. 

Eunicidae,  159. 

Eupagurus,  106. 

Eupomatis,  235. 

Eutamia,  276. 

Even-toed  ungulates,  326. 

Exotic  species,  increase  of,  283. 

Extinct  birds,  313. 

Eyestalks  of  decapods,  121. 


Falcons,  298. 
Fasciolariidse,  175,  177. 
Felis,  328. 
Fiddler  crabs,  110, 123. 


402 


ZOOLOGY 


Fireflies,  51-52,  58,  60. 

Fishes,  230. 

Fissurella,  170. 

Fissurellidae,  177. 

FlageUata,  225,  229. 

Flatfishes,  239-240,  253. 

Flatworms,  153. 

Fleas,  61,70. 

Flicker,  301. 

Flies,  61 ;  degenerate,  70 ;  development 
of,  62;  food  of,  62;  plant-infesting, 
72 ;  mimicry  in,  65 ;  parasites  of,  63 ; 
parasitic,  70;  trachea  of ,  63. 

Flight  of  birds,  310-311. 

Flycatchers,  295. 

Food  of,  beetles,  56;  butterflies,  16; 
crayfish,  98;  earthworm,  134;  fly, 
62 ;  hydra,  207 ;  mouse,  319 ;  English 
sparrow,  282;  starfish,  193;  whale, 
325. 

Forficulidae,  9. 

Formicidje,  34-35,  43. 

Fossil,  birds,  314;  lizards,  272;  man, 
331. 

Fossoria,  34,  43. 

Fowls,  origin  of,  305. 

Fox-sparrow,  285. 

Fresh- water  clam,  178. 

Fresh-water  Cnidaria,  207. 

Fresh- water  jelly-fishes,  208. 

Fringillidge,  284,  317. 

Fringing  reefs,  217. 

Fritillaries,  22. 

Frog,  development  of,  333;  postem- 
bryonic  development  of,  334. 

Frog's  egg,  development  of,  332 ;  heal- 
ing of,  334;  regeneration  of,  334; 
size  of,  332. 

Fulgur,  168,  169,  175. 

Fundulus,  242. 

G 

Gadus,  239. 
Ganoidei,  247-252. 
Ganoids,  252. 
Garpike,  248. 
Garter  snake,  276. 
Gasterosteus,  237-238. 
Gastropoda,  160, 161. 


Gall-gnats,  66,  72. 

Gall-flies,  31. 

Gall-producing  Hymenoptera,  43. 

Gall-wasps,  31,  38-39. 

Galls  on  plants,  67. 

Galley-worm,  76. 

Gallinacei,  304,  314. 

Gallus,  305. 

Gebia,  105. 

Geese,  306. 

Gelasimus,  110-111. 

Genera,  discontinuous,  99-100. 

General  laws  of  development,  335. 

Geometridae,  28,  42. 

Geomys,  320. 

Geophilus,  76. 

Geothlypis,  289. 

Gephyrea,  138-139,  141. 

Germ  theory  of  Infusoria,  223. 

Gibbons,  330. 

Gila  monster,  270-271. 

Giraffes,  326. 

Glossina,  65. 

Glow-worm,  271. 

Glyceridse,  159. 

Gnats,  61. 

Goat-suckers,  301,  303. 

Golden-crowned  kinglet,  287. 

Gopher,  320. 

Gorilla,  330. 

Grallatores,  305,  314. 

Grapta,  21. 

Grasshopper,   1-4  ;    development   of, 

3-4. 

Grass  spiders,  90. 
Gray- veined  white,  18. 
Great  horned  owl,  299. 
Great  northern  shrike,  290. 
Green  frog,  266. 
Grillidfe,  4-5, 15. 
Grillus,  5. 

Ground-beetles,  45-46. 
Grouse,  304. 
Gryllotalpa,  5. 
Guinea  fowl,  304. 
Gulls,  306. 

Gymnophiona,  255,  266,  389. 
Gypsy  moth,  28. 
Gyrinidae,  46,  60, 


INDEX 


403 


H 

Habitat,  of  Auodonta,  178;  butter- 
flies, 16;  Daphnia,  120;  earthworms, 
132 ;  Hydra,  205 ;  slug,  161 ;  Unio,  178. 

Habits,  of  Acrididae,  1;  mouse,  319; 
rat,  319. 

Hadrosaurus,  273. 

Hair  streaks,  22. 

Hairy  ant-eater,  323. 

Hairy  woodpecker,  301. 

Halistemraa,  213. 

Hard-shelled  clams,  190. 

Hares,  321. 

Hawkbill-turtles,  274. 

Hawk-moths,  22,  41. 

Hawks,  298. 

Heating  of  frog's  egg,  334. 

Heat,  effect  on  development,  333. 

Helicidae,  161. 

Helix,  161-165 ;  introduction  of  nemo- 
ralis,  164 ;  variations  in,  164. 

Hellbender,  257,  258. 

Heloderma,  270,  271. 

Hemiptera,  12,  67. 

Hen  clams,  189. 

Hermit  crabs,  105,  107,  123. 

Herons,  305. 

Hessian-fly,  67,68,  82. 

Hesperornis,  313. 

Heterandria,  242. 

Heteroptera,  12. 

Heterotricha,  224,  229. 

Hippa  talpoides,  107. 

Hippidas,  107,  123. 

Hippoboscidae,  70. 

Hippopotamus,  326. 

Hirudinidse,  292,  316. 

Holothurians,  201. 

Holothuroidea,  204. 

Holotrichia,  229. 

Homarus,  100,  113.    . 

Homoptera,  13-14. 

Honey  bees,  32-33. 

Horn-pout,  241. 

Horned  corydalis,  12. 

Horned  fly,  72. 

Horned  toad,  269. 

Hornet,  34. 

Horses,  327;  fossil,  327. 


Horse-flies,  65,  72. 

House-fly,  61. 

House  wren,  288. 

Humming-birds,  301. 

Hydra,  205,  335;  description  of,  205- 

207;  food  of,  207;   habitat  of,  205; 

regeneration  of,  219. 
Hydractinia,  209. 
Hydrocorallidte,  208,  220. 
Hydroidre,  220. 
Hydromedusse,  212,  220. 
Hydrophilidse,  60. 
Hydrophilus,  47. 
Hydrozoa,  220. 
Hyenas,  328. 
Hygrotrechus,  12. 
Hylidae,  263. 
Hymenoptera,  30,  72;  gall-producing, 

43 ;  parasitic,  38, 43 ;  plant-eating,  43. 
Hypotricha,  229. 


Ichneumon  flies.  30. 
Icteridae,  293,  317. 
Idylia,  219. 
Iguanidse,  268-269. 
Importation  of  mouse,  318. 
Increase  of  exotic  species,  283. 
Indigo  bird,  285. 
Infusoria,  222,  229. 
Insectivora,  327,  331. 
Intelligence  of  ants,  35. 
Iphiclides,  18. 
Isopoda,  112. 

J 

Jay,  294. 

Jelly-fishes,  fresh-water,  208 ;  life  his- 
tory of,  210 ;  salt-water,  208. 
Jigger,  71,  95. 
Jingle  shells,  191. 
Julidae,  79. 
Julus,  76,  77,  79. 
Jumping  mice,  321. 
Jumping  spiders,  90,  91,  96,  321. 
June-bugs,  50. 


Kallima,  20. 
Katydids,  6,  15. 


K 


404 


ZOOLOGY 


Key  to  classes  of  Echinodermata,  203 ; 
principal  families  of  Acrididae,  2; 
Coleoptera,  58-61 ;  Hymenoptera, 
42-43 ;  Lamellibranchiata,  188 ;  Lepi- 
doptera,  41-42;  Myriapods,  78;  Or- 
thoptera,  14;  Polychaeta,  159;  Pul- 
monates,  161 ;  principal  genera  of 
Daphnidae,  126;  Lamellibranchiata, 
191 ;  to  genus  Lithobius,  79 ;  to  chief 
orders  of  Birds,  314-317;  Entomos- 
traca,  130;  Gastropoda,  160;  Mala- 
costraca,  122 ;  species  of  Earthworm , 
143 ;  of  Lithobius,  79. 

Killer  whale,  325. 

Killifish,  habits,  food  of,  242. 

Kingbird,  296. 

Kingfisher,  1300. 

Kitchen-middens,  188. 


Lacerta,  270. 

Lacertidae,  270. 

Lachnosterna,  50. 

Ladybird  beetles,  55,  61. 

Lamellibranchiata,  key  to  families  of, 
188. 

Lamellicornidae,  58. 

Lamellicorn  beetles,  49-50,  58 ;  leaf- 
eating,  50 ;  scavengers,  50. 

Lamprey,  245. 

Lamprey  eels,  252. 

Lampyridae,  51,  60. 

Land-locked  fishes,  230. 

Language  of  ants,  36. 

Laniidae,  289,  316. 

Lanius,  290. 

Larks,  295. 

Larval  habits,  of  beetle,  45;  grass- 
hopper, 3-4 ;  lobster,  116. 

Laterigradae,  89, 96. 

Leaf  beetles,  61. 

Leaf-cutting  ants,  37-38. 

Leaf-eating  lamellicorns,  50. 

Leaf-hopper,  44. 

Leaf-miners,  42. 

Leaf-rollers,  42. 

Lecanium,  13. 

LedidaB,  187,  188, 191. 


Leeches,  139-140. 

Lemurs,  329. 

Leopards,  328. 

Leopard  frog,  266. 

Lepidonotus,  147-148,  159. 

Lepidosteus,  248. 

Libinia,  108. 

Life  history,  of  mosquito,  68 ;  Union* 
idae,  179-180. 

Light,  effect  of,  on  development,  333. 

Limacidae,  161. 

Limacinidae,  177. 

Limax,  161-164. 

Limnaea,  habitat  of,  166. 

Limnaeidae,  161. 

Limpets,  170,  177;  economic  impor- 
tance of,  170. 

Limulus,  114. 

Line-weavers,  87,  96. 

Liobunum,  93-94. 

Lions,  328. 

Lithobiidae,  78. 

Lithobius,  74,  75,  78,  79. 

Littorina,  167-168,  175;  littoria,  intro- 
duction, 167 ;  range,  167 ;  spread,  283. 

Littorinidae,  175. 

Liver-flukes,  153-154;  life  history  of, 
154-155 ;  stages  of,  156. 

Lizards,  268 ;  fossil,  272. 

Llamas,  326. 

Lobster,  100,  103,  113;  abnormalities 
in,  119;  development  of,  115;  em- 
bryos of,  116 ;  enemies  of,  102 ;  moult- 
ing of,  103 ;  protection  of,  102. 

Locust  borer,  55. 

Locusts,  14,  15 ;  of  old  world,  2. 

Locustidae,  1, 15. 

Loligo,  172. 

Long-horned  beetles,  54. 

Long-horned  grasshoppers,  15. 

Long-horns,  61. 

Lophobranchii,  244,  253. 

Lost  parts,  regeneration  of,  118. 

Louse-fly,  70. 

Loxia,  284. 

Lucanidae,  49,  58. 

Lucanus,  49. 

Lucius,  243. 

Lumbriculidae,  144. 


INDEX 


405 


Lycaenas,  22. 
Lycosa,  91. 
Lycosida,  92. 
Lynceidae,  131. 
Lynx,  328. 


M 


Macaque,  330. 

Macrodactylus,  50. 

Macrolepidoptera,  22. 

Mactra,  183. 

Mactridae,  182, 189. 

Maggots,  rat-tailed,  65. 

Malacostraca,  97,  111,  125. 

Maldanidse,  159. 

Mammalia,  318,  331. 

Manatee,  324. 

Mandrills,  330. 

Mantidae,  8,  14. 

Margaritana,  191. 

Marmosets,  324. 

Marsupalia,  322,  331. 

Martens,  328. 

Maryland  yellow-throat,  288,  289. 

May  beetles,  50. 

May-flies,  10. 

Meadow  grasshopper,  6. 

Meadow-lark,  293. 

Meal-beetles,  61. 

Meal-worms,  52. 

Mealy  bug,  14. 

Measuring-worms,  42. 

Medusa,  211. 

Megascops,  298. 

Melampus,  161,  176. 

Melanoplus,  2. 

Meloidae,  61. 

Melophagus,  70. 

Metacrinus,  202. 

Metallic  wood-borers,  51,  60. 

Metamorphosis,  of  Amphibia,  260 ;  Ano- 
donta,  180;  beetles,  44;  crayfish, 
117;  dragon-flies,  9;  fly,  63;  frog, 
335 ;  Hemiptera,  12 ;  Lepidoptera,  16 ; 
liver-fluke,  152 ;  lobster,  116 ;  Neu- 
roptera,  11 ;  Orthoptera,  1 ;  starfish, 
194. 

Metridium,  214,  215. 

Microhydra,  208. 


Microlepidoptera,  22. 

Midgets,  62. 

Migrations  of  birds,  309. 

Milk-snake,  276. 

Mimicry,  18-21 ;  flies,  65. 

Minks,  328. 

Minnows,  242,  253. 

Minyas,  214. 

Mniotilidse,  287. 

Mocking-bird,  287. 

Modiola,  185. 

Mole  crabs,  123. 

Mole  cricket,  5. 

Mollusca,  160,  178. 

Monarch,  22. 

Mongoose,  328. 

Monkeys,  330. 

Monotremata,  321. 

Morone,  234. 

Morula,  336. 

Mosquito,  68. 

Motacillidae,  317. 

Moths,  22. 

Moulting,  103. 

Mourning  cloak,  21. 

Mouse,  distribution  of,  318 ;  food  of,  319 ; 

habits  of,  319 ;  importation  of,  318. 
Mud-daubing  wasp,  82. 
Mud  eel,  255,  256. 
Mud  fishes,  252. 
Mud  puppy,  257. 
Mud  wasps,  34,  43. 
Muricidae,  169,  175. 
Mus,  321. 

Muscidae,  61,  64,  72. 
Muskallunge,  242. 
Muskrat,  321. 
Musk  turtle,  276. 
Mussels,  120,  190. 
Mustelus,  246. 
My  a,  182,  183. 
Myidaa,  182, 189. 
Myrmica,  37. 
Mytilidge,  184, 190. 

N 

Naidae,  144. 
Nais,  137-138, 144. 
Narcomedusae,  221. 


406 


ZOOLOGY 


Natatores,  305,  3U. 

Natica,  168, 175. 

Naticidse,  175,  170. 

Nautilus,  173. 

Nebalia,  122. 

Necturus,  257,  335. 

Nemathelminthes,  386. 

Nematocera,  61,  66. 

Nematus,  eggs  of,  40. 

Nemertini,  158. 

Nephelis,  140. 

Nereida,  159. 

Nereis,  136,  138,  145,  .146,  159;  food 
and  habitat  of,  145.  ' 

Nest,  of  barn-swallow,  292;  of  chim- 
ney-swift, 302 ;  of  pewee,  296. 

Neuroptera,  11-12. 

Newts,  254,  362;  how  to  capture,  255. 

Night-hawk,  303. 

Nightingale,  285. 

Nile  varan  us,  269. 

Noctuidae,  27-28,  41. 

Norwegian  lobster,  113. 

Notodelphys,  263. 

Notolophus,  28. 

Nuculidae,  191. 

Nuthatches,  286. 

Nymphs,  21. 


O 

Obelia,  210. 

Odd-toed  ungulates,  327. 

Odonata,  9. 

(Estridae,  64. 

Oligochaeta,  132,  136,  139. 

Oniscus,  112. 

Operculum,  of  worms,  151 ;  of  fish, 
233. 

Ophidia,  280. 

Ophion,  39. 

Ophiuroidea,  198,  203. 

Opisthobranchiata,  161. 

Opisthobranchs,  164,  170-171;  degen- 
eration of  shell  of,  162. 

Opossum,  322-323. 

Orang-utan,  330. 

Orbitelariae,  86,  96. 

Orb-weavers,  86,  96. 


Orbweb,  diagram  of,  86;  of  Epiera, 
87 ;  nomenclature  of  parts  of,  86. 

Orbweb  spiders,  80. 

Orca,  325. 

Orchard  oriole,  293. 

Orchelium,  6. 

Ornithorhynchus,  321. 

Orthoptera,  1. 

Orthosoma,  54. 

Osmerus,  230. 

Ostracoda,  127,  131. 

Ostrea,  187. 

Ostreidae,  190;  economic  importance 
of,  187. 

Ostrich,  307;  habits  of,  307-308. 

Otter,  328. 

Owlet  moths,  27-28,  41. 

Owls,  298. 

Oxen,  326. 

Oxyrhyncha,  123. 

Oyster  drill,  169. 

Oysters,  187-188,  190. 


Paddlefish,  247. 

Paguridse,  105,  123. 

Painted  turtle,  276. 

Palaeinonetes,  104. 

Paliuurus,  101. 

Pallene,  95. 

Palm-crab,  107. 

Pandoridae,  189. 

Pandorus,  23. 

Panopeus,  109. 

Papilionidae,  41. 

Papilio,  21. 

Paramecium,  222,  229;    food  of,  224; 

fusion  of,  229;  habitat  of,  224;  rate 

of  division,  229. 
Parasites  of  fly,  63. 
Parasitic,  flies,  70;  Hymenoptera,  43; 

worms,  158. 
Paridaj,  286,  316. 
Parrots,  297. 
Partridges,  304. 
Passenger  pigeon ,  303. 
Passer,  281-282. 
Passeres,  315. 


INDEX 


407 


Patella,  170. 

Pauropus,  77. 

Pearl-bearers,  185 ;  fishery,  185-18(5. 

Peccaries,  326. 

Pecten,  186. 

Pectiuatella,  143. 

Pectinidse,  190-191;  locomotion  of,  186. 

Pedicellina,  141. 

Pelicans,  306. 

Perches,  235,  252. 

Peritricha,  229. 

Petrels,  306. 

Petricolidae,  189. 

Petromyzon,  245. 

Pewee,  296 ;  nest  of,  296. 

Pheasants,  304 ;  range  of,  305. 

Phalangina,  93. 

Pharyngognathi,  93. 

Phasmidse,  7,  15. 

Phasmomantis,  8. 

Philampelus,  23. 

Philinidje,  176. 

Phoca,  328. 

Pholadidje,  181,  188. 

Pholis,  237. 

Photuris,  52. 

Phrynosoma,  269. 

Physa,  161,  167;  food  of,  166;  habitat 

of,  166. 
Physalia,  213. 

Physiological  division  of  labor,  120. 
Physostomi,  253. 
Phytophaga,  43. 
Pickerels,  242. 
Pickerel  frog,  266. 
Pieris,  21 ;  rapse,  increase  and  spread 

of,  283. 
Pigeons,  304. 
Pigs,  3136. 
Pike,  242. 
Pimpla,  37. 
Pin  worm,  153. 
Pine  borers,  53. 
Pinnotheres,  109-110. 
Pipa,  262 ;  with  embryos,  263. 
Pipe-fishes,  244,  253. 
Pipidse,  263. 
Piranga,  293. 
Piroplasma,  228. 


Pisidium,  191. 

Pithecanthropus,  331. 

Planarians,    abnormalities    of,     155; 

fresh-water,  153;    regeneration  of, 

154. 
Planorbis,  167;   eggs  and  habitat  of, 

167. 

Plant-eating  hymenoptera,  43. 
Plant  galls,  67. 
Plant  lice,  14. 
Platyonichus,  110. 
Platypsylla,  56. 
Plectognathi,  253. 
Plethodon,  259. 
Plethodontidse,  259,  267. 
Pleurodelidse,  267. 
Pleurotomidse,  176. 
Plovers,  habitat  of,  305. 
Plumatella,  142. 
Plume-moths,  42. 

Podophora,  food  and  habitat  of,  225. 
Podopthalmata,  122. 
Poisonous  spiders,  91-92. 
Polistes,  33. 
Polychseta,  136, 148. 
Polycirrus,  149-150. 
Polydesmidse,  79. 
Polydesmus,  77,  79. 
Polymorphism  in  butterflies,  17. 
Polyphemidse,  131. 
Polyxenidse,  78. 
Polyzoniidse,  79. 
Pond  snail,  habitat  of,  166. 
Portuguese  man-of-war,  213-214. 
Postembryonic  development  of  frog, 

334. 

Pouched  gopher,  320. 
Prairie  dog,  320. 
Prawns,  104,  124. 
Praying-mantis,  8,  14. 
Primates,  329,  331. 
Prionus,  54. 
Prosobranchiata,  160. 
Protection,  of  birds,  312;  of   lobster, 

102. 

Protective  resemblance,  18-21. 
Proteidae,  257,  266. 
Protozoa,  222;  relations  to  man,  228; 

reproductive  capacity  of,  228. 


408 


ZOOLOGY 


Psammobiidse,  189. 

Psittaci,  297,  315. 

Psoroptes,  94. 

Pterophoridae,  42. 

Pulex,  70. 

Pulmonata,  160, 161, 164, 165;  aquatic, 

166. 

Pumpkin-seed  sunfish,  236. 
Pupa,  16,  165. 
Pupidse,  385. 
Pupipara,  61. 
Purple  grackle,  294. 
Pyralidse,  29,  42. 
Pyramidellidse,  174. 


Quail,  304. 
Quadrate,  232. 
Quiscalus,  294. 


Q 


Raccoons,  328. 

Races  of  tame  mice,  319-320. 

Rails,  305. 

Rana,  265. 

Ranida3,  range  of,  265. 

Raptores,  298,  315. 

Rat,  habits  of,  319. 

Rat-tailed  maggots,  65. 

Rattlesnake,  278. 

Rays,  252. 

Razor  clams,  188. 

Razor  shell,  182. 

Red-eyed  vireo,  289-290. 

Red-headed  woodpecker,  301. 

Reefs:  barrier,  coral,  fringing,  217. 

Redpoll  warbler,  288. 

Red-winged  blackbird,  293. 

Reduvius,  12. 

Regal  moth,  25. 

Regulus,  287. 

Regeneration,  of  earthworms,  134;  flat 
worms,  153 ;  frog's  egg,  334 ;  Hydra, 
219 ;  lost  parts  of  lobster,  118 ;  plan- 
arians,  154. 

Relationships  of  earthworms,  132. 

Reproductive  capacity  of  protozoa,  228. 

Reproduction,  332. 

Reptiles,  268. 

Resistance  of  earthworms,  134. 


Retitelariae,  87,  96. 

Rhea,307. 

Rhinoceroses,  327. 

Rhizopoda,  229. 

Rice  bird,  294. 

Rissoida3, 174. 

Robber-flies,  65,  72,  73. 

Robin,  285. 

Rock-eel,  236,  237. 

Rodentia,  320,  331. 

Rodents,  320. 

Rose-breasted  grosbeak,  285. 

Rose-bug,  50-51. 

Round  worms,  151. 

Routes  of  bird  migration,  309. 

Rove  beetles,  47,  57,  58. 

Ruby-crowned  kinglet,  285. 

Ruby-throated  humming-bird,  302. 

Ruffed  grouse,  304. 

Runners,  60. 

Running  beetles,  45. 

Running  spiders,  91,  96 ;  habits  of,  89= 


Salmo,  233;  skull  of,  232. 
Salmonidae,  230,  231 ;  distribution  of, 

231 ;  spawning  of,  231-233. 
Salamander,  259. 
Saltigradfe,  90,  96. 
Sand  dollars,  200-201. 
Sandpipers,  305. 
Sauria,  268,  280. 
Saw-fly,  eggs  of,  40 ;  larvae,  39. 
Saxicavidae,  189. 
Saxicolidae,  315. 
Scalariidae,  174. 
Scale  bug,  14. 
Scale  insect,  13. 
Scaled  worm,  148. 
Scallops,  190. 
Scaly  ant-eater,  323. 
Scansores,  299,  315. 
Scaphandridae,  176. 
Scarlet  tanager,  293. 
Scavengers,    Diptera,    72;     Lamelli- 

corns,  50. 

Schizopod  larva,  116. 
Schizoneura, 14. 
Scolopendra,  75,  76,  78. 


INDEX 


409 


Scolopendrella,  78. 

Scolopendridae,  78. 

Scolytidae,  53,  61. 

Screech  owl,  298,  299. 

Sculpin,  236,  252. 

Scutigera,  75,  78. 

Scutigeridae,  78. 

Scyphozoa,  214, 220. 

Sea-cows,  324. 

Sea-crayfish,  113. 

Sea-cucumbers,  204. 

Sea-lilies,  203. 

Sea-lions,  329. 

Sea-mats,  218. 

Sea-mouse,  148. 

Sea-spiders,  107. 

Sea-squirts,  218. 

Sea-urchins,  204 ;  food  and  habitat  of, 

199-200. 

Sea-walnuts,  219. 
Seal,  328, 329. 
Searcher,  46. 

Sedentary  polychaeta,  148. 
Selachians,  246. 
Selachii,  252. 
Semelidse,  189. 
Serpent  stars,  203;    description    and 

habitat  of,  199. 
Serpula,  151,  159;  tube,  151. 
Serpulidae,  159. 
Sertularia,  210. 
Sexton  beetles,  48. 
Sexual  dimorphism  of  spiders,  92. 
Shad,  253;  range,  243-244. 
Sharks,  252. 

Sharp-shinned  hawk,  298. 
Sheep,  326. 
Sheep-tick,  70. 
Sheep  scab,  94. 
Shipworms,  188. 
Short-horned  diptera,  64. 
Short-horned  grasshoppers,  51. 
Short-winged  beetles,  47. 
Shrews,  food  of,  327. 
Shrike,  289. 
Shrimps,    104,  124;    value  of   catch, 

111. 

Sididae,  131. 
Silk-worms,  42. 


Silpha,  48. 

Silphidse,  48,  60. 

Silversides,  236,  252. 

Simia,  330. 

Simuliidae,  67. 

Simulium,  67. 

Siphonophora,  212-213,  220. 

Siphonata,  178. 

Siren,  255,  256. 

Sirenia,  331. 

Sirenidfe,  255,  266. 

Sitta,  287. 

Sittidae,  316. 

Skunks,  328. 

Sloths,  323;  two-toed,  324. 

Slugs,  132, 160,  162 ;  apparent  absence 

of  shell  in,  162;  economics  of,  162; 

food  of,  161-162;    habitat  of,  161; 

species  of,  162. 
Smelt,  230,  253 ;  artificial  propagation 

of,  231 ;  economic  importance  of,  230; 

habitat  of,  230;   range  of  Atlantic 

form  of,  230-231;  value  of  Atlantic 

fishery,  231. 
Snapping  beetles,  51. 
Snapping  turtles,  275. 
Snipes,  habitat  of,  305. 
Snout  beetles,  61. 
Snow-bird,  285. 
Snowy  owl,  299. 
Social  bees,  31. 
Social  life  of  ants,  36. 
Soft-shelled  clams,  189. 
Solaster,  197-198. 
Solemyidae,  189. 
Solenidae,  182, 188. 
Song-sparrow,  285. 
Song-thrush,  285. 
Sow-bug,  112. 
Spanish  fly,  58. 
Sparrow-hawk,  299. 
Speckled  tortoise,  276. 
Spelerpes,  color  of,  259;  development 

of,  261-262 ;  habitat  of,  260. 
Sphex,  82. 
Sphingidae,  22,  41. 
Sphinx  moth,  23. 
Spiders,  80,  92 ;  ballooning  habits  of, 

83-84;  classification  of,  85;  food  of, 


410 


ZOOLOGY 


82;  poisonous,  91-92 :  sexual  di- 
morphism of,  92 ;  spinning  habits  of, 
83;  wandering,  8K. 

Spider-crabs,  107,  123. 

Spider  webs,  economic  importance  of, 
90. 

Spinning  habits,  in  spiders,  83. 

Spiny  ant-eater,  322. 

Spiny  lobster,  101. 

Spirulidaj,  174. 

Spizella,  285. 

Sponges,  205. 

Spontaneous  generation  theory,  223. 

Spoonbill,  habitat  of,  247. 

Spore  of  Infusoria,  223. 

Sporozoa,  227,  229. 

Spotted  sandpiper,  306. 

Spreading  adder,  276. 

Spring  azures,  18,  22. 

Square  crabs,  123. 

Squash  bug,  13. 

Squids,  171. 

Squilla,  111. 

Squirrel,  320. 

Stable-fly,  61. 

Stag-beetles,  49,  58. 

Staphylinidse,  47,  58. 

Starfish,  192,203;  abnormalities  of ,  196; 
development  of,  193-194;  distribution 
and  habitat  of,  192;  economic  im- 
portance of,  193 ;  food  of,  193 ;  larval 
stages  of,  195;  metamorphosis  of, 
195 ;  systematic  position  of,  192. 

Stentor,  229 ;  habitat  of,  224-225. 

Sterna,  307. 

Sticklebacks,  238,  252. 

Stomatopoda,  111,  122. 

Storks,  305. 

Strongylocentrotus,  199. 

Sturgeons,  247 ;  economic  importance, 
habitat,  food  of,  247. 

Suckers,  241,  253. 

Suctoria,  225,  229. 

Sunfish,  235,  252. 

Swallows,  292. 

Swarm  of  bees,  32. 

Swifts,  301,  302. 

Sycon,  206. 

Syllidee,  159. 


Sylvicolidse,  317. 
Sylviidse,  285,  315,  316. 
Synapta,  202,  203. 
Synotus,  329. 
Syrphidse,  66,  73. 
Syrpus,  64. 


Tabanidse,  65. 

Tabanus,65,  66. 

Tsenia,  157. 

Talorchestia,  112. 

Tanagers,  292. 

Tanagridse,  292. 

Tapeworm,  156 ;  human,  157. 

Tapirs,  327. 

Tarantula,  92. 

Teeth  of  fossil  birds,  314. 

Teleostei,  252. 

Tellinidse,  190. 

Tenebrio,  52. 

Tenebrionidse,  52,  61. 

Tent  caterpillars,  26;   egg  masses  of, 

26 ;  nests  of,  27. 
Terebellidaj,  159. 
Teredidse,  181,  188. 
Teredo,  181. 
Termes,  11. 
Termites,  11.      .. 
Terns,  306,  307. 
Terrapene,  275. 
Territelarise,  85,  95. 
Testudinidse,  275. 
Texas  fever  in  cattle,  228. 
Thalassinidae,  105,  124. 
Theclas,  22. 

Theridium,  80,  82;  food  of,  82. 
Thomisus,  90. 
Thrushes,  385. 
Tineidse,  29,  42. 
Tigers,  328. 
Tiger-beetles,  45. 
Tiger-moths,  24,  41. 
Tipulidae,  68-69. 
Titmice,  286. 

Toadtishes,  252 ;  habitat  of,  236. 
Tornatinidae,  176. 
Tortricidse,  29,  42. 
Toucans,  299. 


INDEX 


411 


Trachea  of  fly,  63. 

Tracheata,  387. 

Trachina,  152,  153. 

Trachomedusae,  221. 

Trap-door  spiders,  80. 

Tree-hoppers,  14. 

Trematoda,  385. 

Trepangs,    economic    importance    of, 

202. 

Tree-sparrow,  285. 
Tree-toad,  265. 
Triangular  crabs,  123. 
Triforidae,  177. 
Trilobites,  130. 
Trionychidae,  274. 
Trionyx,  275. 
Trochidae,  175. 
Trochilus,  302. 
Troglodytidae,  287,  316. 
Troglodytes,  288. 
T  routs,  233,  253. 
True  bugs,  12. 
True  wasps  83. 
Tsetse-fly,  64. 
Tube-forming  worms,  102. 
Tube-weavers,  88,  96. 
Tubifex,  136,  144. 
Tubificidae,  144. 
Tubitelariae,  88,  96.    . 
Tubularia,  208. 
Tubularian  hydroid,  210. 
Tubularidaj,  208,  221. 
Tumble-bugs,  50,  57. 
Tunicata,  218,  251. 
Tunnel-weavers,  85,  95. 
Turbellaria,  385. 
Turdidge,  285,  315,  316. 
Turdus,  286. 
Turkey-buzzard,  299. 
Turkeys,  304;  wild,  305. 
Turtles,  273;  range  of ,  274. 
Tussock  moth,  28". 
Twin-spotted  sphinx,  23. 
Tyrannidae,  295,  315. 
Tyranuus,  296. 

Unau,  324. 

Ungulata,  325,  331;    even-toed,  326; 
odd-toed,  327. 


Unio,  178,  191. 

Unionidas,  179,  180,  191. 

Urodela,  255, 266 ;  development  of,  261. 

Urosalpiux,  169,  175. 


Varanidae,  269. 
Variations  in  Helix,  1(55. 
Veneridae,  180,  183,  190. 
Venus,  183. 
Vermetidae,  174. 
Vertebrates,  ancestry  of,  248. 
Vespa,  34,  35. 
Vesper  sparrow,  285. 
Vesperidae,  43. 
Vespidae,  33. 
Vireo,  288,  290. 
Vireonidae,  288,  316,  317. 
Volvox,  226,  227. 
Von  Baer's  law,  336. 
Vorticella,  225,  229. 
Vultures,  298,  299. 

W 

Walking-sticks,  7,  15. 

Wall-eyed  pike,  235. 

Walruses,  329. 

Wandering  spiders,  88. 

Warblers,  285. 

Wasps,  30,  33,  43;  social,  33. 

Water-dog,  257.. 

Water  moccasin,  279. 

Water  scavengers,  60. 

Water  snakes.  271. 

Water  strider,  12. 

Weasels,  328. 

Weevils,  57. 

Whales,  324;  feeding  habits  of.  325. 

Whippoorwill,  303. 

Whirligig,  60. 

White  ants,  11. 

White-breasted  nuthatch,  287. 

Whitefishes,  234,  253. 

White-lined  horse-fly,  6(5. 

WThite-throated  sparrow,  285. 

Wingless  birds,  307. 

Wingless  cockroach,  8. 

AVood-borers,  41. 


412 


ZOOLOGY 


Woodchuck,  320. 
Wood  frog,  266. 
Woodpeckers,  301. 
Wood-tortoise,  276. 
Wood-thrush,  286. 
Wood-warblers,  287. 
Worms,  tube-forming,  102. 
Wrens,  287. 

X 

Xylotropidae,  23,  41. 


Yellow  bird,  285. 
Yellow  warbler,  288. 
Yoldia,  187,  188. 


Zebra,  327. 

Zebra  swallow-tail,  18. 
Zygaenidae,  41. 
Zygodactyla,  212. 


A  TEXT-BOOK  OF  ZOOLOGY 


BY 

T.  JEFFERY  PARKER,  D.Sc.,  F.R.S. 

Professor  of  Biology  in  University  of  Otago,  Dunedin,  N.Z. 


WILLIAM  A.   HASWELL,   M.A.,  D.Sc.,  F.R.S. 

Professor  of  Biology  in  the  University  of  Sydney,  N.S.W. 

In  two  volumes,  containing  many  illustrations 

Cloth.     8vo.     2  vols.      $9.OO,  net 


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ber of  those  whose  main  interest  lies  in  other  branches  of  scientific 
study.  Written  with  a  clearness,  accuracy,  and  method  of  a  practised 
teacher,  it  is  admirably  illustrated  with  a  profusion  of  figures  —  there 
are  nearly  twelve  hundred  in  all  —  of  the  highest  excellence." 

—  Science. 

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qualifiedly conceded,  represents  an  enormous  amount  of  labor  upon 
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admirable  mechanical  features  of  the  work  and  the  educational  por- 
tent of  the  issue  of  so  large  and  costly  a  text-book  upon  a  single 
branch  of  natural  history.  The  intent  and  method  of  the  authors  are 
clearly  set  forth  in  the  preface.  After  a  general  introduction  and  a 
section  upon  '  General  Structure  and  Physiology,'  there  are  presented 
in  turn  the  twelve  phylums  recognized,  viz. :  Protozoa,  Porifera,  Coelen- 
terata,  Platyhelminths,  Nemathelminths,  Trochelminths,  Molluscoida, 
Echinodermata,  Annulata,  Arthropoda,  Mollusca,  and  (occupying  the 
whole  of  the  second  volume)  Chordata,  corresponding  nearly  with 
Vertebrates.  The  discussion  of  each  class  is  based  upon  a  more  or  less 
detailed  account  of  the  anatomy  and  development  of  one  or  more 
forms,  fairly  representative  and  commonly  available.  The  second 
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to  Geographic  Distribution,  the  Philosophy  and  History  of  Zoology, 
and  Modern  Literature;  seven  of  the  sixty  writers  recommended  being 
American."  —  The  Nation. 


THE    MACMILLAN    COMPANY 

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EXPERIMENTAL  MORPHOLOGY 

BY 

CHARLES  BENEDICT  DAVENPORT,  Ph.D. 

Instructor  in  Zoology  in  Harvard  University 


PART   I. 

Effects  of  Chemical  and 
Physical  Agents  upon 
the  Protoplasm 

Cloth.    8vo.    $2.6O,  net 


PART  ii.    --: 

Effects  of  Chemical  and 
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Growth 

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criticisms  of  the  methods  employed  in  experimentation,  and  the 
bibliographical  lists  at  the  conclusion  of  each  chapter,  con- 
tribute materially  to  the  value  the  book  possesses  for  both  the 
morphologist  and  the  physiologist."  —  Science. 

"  In  this  second  instalment  of  his  valuable  treatise,  Dr. 
Davenport  considers  the  effects  of  chemical  and  physical  agents 
on  growth.  Plants  lend  themselves  so  readily  to  observations 
respecting  growth  that  they  have  received  from  Dr.  Davenport 
a  degree  of  attention  in  this  work  which  compels  the  student 
of  plant  physiology  to  accept  his  aid.  On  the  whole,  the  edi- 
torial work  has  been  wonderfully  well  done,  and  the  errors  are 
so  few  that  they  need  not  be  mentioned  here ;  they  do  not 
appear  likely  to  mislead  seriously  any  students  who  make  use 
of  the  vast  amount  of  material  which  has  been  gathered 
patiently,  and  for  the  most  part  has  been  well  arranged." 

—  American  Journal  of  Science. 


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THIS  BOOK  IS  DUE  ON  THE  LAST  DATE 
STAMPED  BELOW 


5161 


SUB  29  1918 

FEB    3  1921 
fcl 


NOV  14  IS27 
OEC  2  1 


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NQV251968 


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BIOLOGY 


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